proofs/containers/balanced_search_tree/setters.bend

bend-collections-laws-containers@1.0.0.0 · 729 lines · 0 definitions

1import Base
2import bend-collections-laws-containers@1.0.0.0/proofs/lib/logic.bend as L
3import bend-collections-laws-containers@1.0.0.0/proofs/lib/nat.bend as N
4import bend-collections-laws-containers@1.0.0.0/proofs/lib/order.bend as O
5import bend-collections-laws-containers@1.0.0.0/spec/lib/common.bend as SC
6import bend-collections-laws-containers@1.0.0.0/src/containers/balanced_search_tree.bend as M
7import bend-collections-laws-containers@1.0.0.0/proofs/containers/balanced_search_tree/state.bend as ST
8import bend-collections-laws-containers@1.0.0.0/proofs/containers/balanced_search_tree/prim.bend as PR
9import bend-collections-laws-containers@1.0.0.0/proofs/containers/balanced_search_tree/mirror.bend as MI
10import bend-collections-laws-containers@1.0.0.0/proofs/containers/balanced_search_tree/frame.bend as FR
11import bend-collections-laws-containers@1.0.0.0/proofs/containers/balanced_search_tree/agree.bend as AG
12import bend-collections-laws-containers@1.0.0.0/spec/containers/balanced_search_tree/main.bend as S
13import bend-collections-laws-containers@1.0.0.0/proofs/containers/balanced_search_tree/ends.bend as EN
14import bend-collections-laws-containers@1.0.0.0/proofs/containers/balanced_search_tree/path.bend as P
15import bend-collections-laws-containers@1.0.0.0/proofs/lib/nat_list.bend as NL
16
17# The mirror's node setters as functions of the node list: each rewrites one
18# field of an id's node (nothing for a free or absent node). The written
19# node, the length, and agreement off the id.
20# (source: tools/generators/tm_hand/setters.src)
21
22
23# ---- left ----
24
25def setl_n(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, x: M.Node<K>) -> List<&2, M.Node<K>>:
26  match x:
27    case M.Free{f}:
28      nl
29    case M.N{+c, +a, +b, +q, +k}:
30      PR.wr_nl(K, nl, id, M.N{c, v, b, q, k})
31
32def setl(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> List<&2, M.Node<K>>:
33  setl_n(K, nl, id, v, ST.nd(K, nl, id))
34
35def set_left_node_m(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, +n: Nat, +root: Nat, +lo: Nat, +hi: Nat, +free: Nat, +l: Nat, +d: Nat, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +tg: ST.Tr, +fl: List<&2, Nat>, +id: Nat, +v: Nat, +x: M.Node<K>) -> {MI.set_left_node(~K, ~V, ~cmp, ST.SH{n, root, lo, hi, free, l, d, nl, pl, tg, fl}, id, v, x) == ST.SH{n, root, lo, hi, free, l, d, setl_n(K, nl, id, v, x), pl, tg, fl} : ST.Sh<K, V>}:
36  match x:
37    case M.Free{f}:
38      {==}
39    case M.N{c, a, b, q, k}:
40      {==}
41
42def set_left_m(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, +n: Nat, +root: Nat, +lo: Nat, +hi: Nat, +free: Nat, +l: Nat, +d: Nat, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +tg: ST.Tr, +fl: List<&2, Nat>, +id: Nat, +v: Nat) -> {MI.set_left(~K, ~V, ~cmp, ST.SH{n, root, lo, hi, free, l, d, nl, pl, tg, fl}, id, v) == ST.SH{n, root, lo, hi, free, l, d, setl(K, nl, id, v), pl, tg, fl} : ST.Sh<K, V>}:
43  set_left_node_m(~K, ~V, ~cmp, n, root, lo, hi, free, l, d, nl, pl, tg, fl, id, v, ST.nd(K, nl, id))
44
45def setl_same(-K: Data, +nl: List<&2, M.Node<K>>, +i: Nat, +v: Nat, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, 1n+i) == M.N{c, a, b, q, k} : M.Node<K>}, +hi: {Nat.is_lt(i, SC.length(M.Node<K>, nl)) == True{} : Bool}) -> {ST.nd(K, setl(K, nl, 1n+i, v), 1n+i) == M.N{c, v, b, q, k} : M.Node<K>}:
46  %Equal.sym(M.Node<K>, ST.nd(K, nl, 1n+i), M.N{c, a, b, q, k}, hx) : {ST.nd(K, setl_n(K, nl, 1n+i, v, _), 1n+i) == M.N{c, v, b, q, k} : M.Node<K>}
47  FR.nd_wr_same(K, nl, i, M.N{c, v, b, q, k}, hi)
48
49def setl_n_len(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +x: M.Node<K>) -> {SC.length(M.Node<K>, setl_n(K, nl, id, v, x)) == SC.length(M.Node<K>, nl) : Nat}:
50  match x:
51    case M.Free{f}:
52      {==}
53    case M.N{+c, +a, +b, +q, +k}:
54      FR.len_wr(K, nl, id, M.N{c, v, b, q, k})
55
56def setl_len(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> {SC.length(M.Node<K>, setl(K, nl, id, v)) == SC.length(M.Node<K>, nl) : Nat}:
57  setl_n_len(K, nl, id, v, ST.nd(K, nl, id))
58
59def setl_n_agr(~K: Data, ~cmp: K -> K -> Cmp, ~o: O.Order(~K, ~cmp), +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +x: M.Node<K>, +hn: {NL.memn(id, xs) == False{} : Bool}) -> {AG.agr(~K, ~cmp, xs, nl, setl_n(K, nl, id, v, x)) == True{} : Bool}:
60  match x:
61    case M.Free{f}:
62      AG.agr_refl(~K, ~cmp, ~o, xs, nl)
63    case M.N{+c, +a, +b, +q, +k}:
64      AG.agr_wr(~K, ~cmp, ~o, xs, nl, id, M.N{c, v, b, q, k}, hn)
65
66# agreement off the written id
67def setl_agr(~K: Data, ~cmp: K -> K -> Cmp, ~o: O.Order(~K, ~cmp), +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +hn: {NL.memn(id, xs) == False{} : Bool}) -> {AG.agr(~K, ~cmp, xs, nl, setl(K, nl, id, v)) == True{} : Bool}:
68  setl_n_agr(~K, ~cmp, ~o, xs, nl, id, v, ST.nd(K, nl, id), hn)
69
70# ---- right ----
71
72def setr_n(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, x: M.Node<K>) -> List<&2, M.Node<K>>:
73  match x:
74    case M.Free{f}:
75      nl
76    case M.N{+c, +a, +b, +q, +k}:
77      PR.wr_nl(K, nl, id, M.N{c, a, v, q, k})
78
79def setr(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> List<&2, M.Node<K>>:
80  setr_n(K, nl, id, v, ST.nd(K, nl, id))
81
82def set_right_node_m(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, +n: Nat, +root: Nat, +lo: Nat, +hi: Nat, +free: Nat, +l: Nat, +d: Nat, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +tg: ST.Tr, +fl: List<&2, Nat>, +id: Nat, +v: Nat, +x: M.Node<K>) -> {MI.set_right_node(~K, ~V, ~cmp, ST.SH{n, root, lo, hi, free, l, d, nl, pl, tg, fl}, id, v, x) == ST.SH{n, root, lo, hi, free, l, d, setr_n(K, nl, id, v, x), pl, tg, fl} : ST.Sh<K, V>}:
83  match x:
84    case M.Free{f}:
85      {==}
86    case M.N{c, a, b, q, k}:
87      {==}
88
89def set_right_m(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, +n: Nat, +root: Nat, +lo: Nat, +hi: Nat, +free: Nat, +l: Nat, +d: Nat, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +tg: ST.Tr, +fl: List<&2, Nat>, +id: Nat, +v: Nat) -> {MI.set_right(~K, ~V, ~cmp, ST.SH{n, root, lo, hi, free, l, d, nl, pl, tg, fl}, id, v) == ST.SH{n, root, lo, hi, free, l, d, setr(K, nl, id, v), pl, tg, fl} : ST.Sh<K, V>}:
90  set_right_node_m(~K, ~V, ~cmp, n, root, lo, hi, free, l, d, nl, pl, tg, fl, id, v, ST.nd(K, nl, id))
91
92def setr_same(-K: Data, +nl: List<&2, M.Node<K>>, +i: Nat, +v: Nat, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, 1n+i) == M.N{c, a, b, q, k} : M.Node<K>}, +hi: {Nat.is_lt(i, SC.length(M.Node<K>, nl)) == True{} : Bool}) -> {ST.nd(K, setr(K, nl, 1n+i, v), 1n+i) == M.N{c, a, v, q, k} : M.Node<K>}:
93  %Equal.sym(M.Node<K>, ST.nd(K, nl, 1n+i), M.N{c, a, b, q, k}, hx) : {ST.nd(K, setr_n(K, nl, 1n+i, v, _), 1n+i) == M.N{c, a, v, q, k} : M.Node<K>}
94  FR.nd_wr_same(K, nl, i, M.N{c, a, v, q, k}, hi)
95
96def setr_n_len(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +x: M.Node<K>) -> {SC.length(M.Node<K>, setr_n(K, nl, id, v, x)) == SC.length(M.Node<K>, nl) : Nat}:
97  match x:
98    case M.Free{f}:
99      {==}
100    case M.N{+c, +a, +b, +q, +k}:
101      FR.len_wr(K, nl, id, M.N{c, a, v, q, k})
102
103def setr_len(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> {SC.length(M.Node<K>, setr(K, nl, id, v)) == SC.length(M.Node<K>, nl) : Nat}:
104  setr_n_len(K, nl, id, v, ST.nd(K, nl, id))
105
106def setr_n_agr(~K: Data, ~cmp: K -> K -> Cmp, ~o: O.Order(~K, ~cmp), +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +x: M.Node<K>, +hn: {NL.memn(id, xs) == False{} : Bool}) -> {AG.agr(~K, ~cmp, xs, nl, setr_n(K, nl, id, v, x)) == True{} : Bool}:
107  match x:
108    case M.Free{f}:
109      AG.agr_refl(~K, ~cmp, ~o, xs, nl)
110    case M.N{+c, +a, +b, +q, +k}:
111      AG.agr_wr(~K, ~cmp, ~o, xs, nl, id, M.N{c, a, v, q, k}, hn)
112
113# agreement off the written id
114def setr_agr(~K: Data, ~cmp: K -> K -> Cmp, ~o: O.Order(~K, ~cmp), +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +hn: {NL.memn(id, xs) == False{} : Bool}) -> {AG.agr(~K, ~cmp, xs, nl, setr(K, nl, id, v)) == True{} : Bool}:
115  setr_n_agr(~K, ~cmp, ~o, xs, nl, id, v, ST.nd(K, nl, id), hn)
116
117# ---- parent ----
118
119def setp_n(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, x: M.Node<K>) -> List<&2, M.Node<K>>:
120  match x:
121    case M.Free{f}:
122      nl
123    case M.N{+c, +a, +b, +q, +k}:
124      PR.wr_nl(K, nl, id, M.N{c, a, b, v, k})
125
126def setp(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> List<&2, M.Node<K>>:
127  setp_n(K, nl, id, v, ST.nd(K, nl, id))
128
129def set_parent_node_m(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, +n: Nat, +root: Nat, +lo: Nat, +hi: Nat, +free: Nat, +l: Nat, +d: Nat, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +tg: ST.Tr, +fl: List<&2, Nat>, +id: Nat, +v: Nat, +x: M.Node<K>) -> {MI.set_parent_node(~K, ~V, ~cmp, ST.SH{n, root, lo, hi, free, l, d, nl, pl, tg, fl}, id, v, x) == ST.SH{n, root, lo, hi, free, l, d, setp_n(K, nl, id, v, x), pl, tg, fl} : ST.Sh<K, V>}:
130  match x:
131    case M.Free{f}:
132      {==}
133    case M.N{c, a, b, q, k}:
134      {==}
135
136def set_parent_m(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, +n: Nat, +root: Nat, +lo: Nat, +hi: Nat, +free: Nat, +l: Nat, +d: Nat, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +tg: ST.Tr, +fl: List<&2, Nat>, +id: Nat, +v: Nat) -> {MI.set_parent(~K, ~V, ~cmp, ST.SH{n, root, lo, hi, free, l, d, nl, pl, tg, fl}, id, v) == ST.SH{n, root, lo, hi, free, l, d, setp(K, nl, id, v), pl, tg, fl} : ST.Sh<K, V>}:
137  set_parent_node_m(~K, ~V, ~cmp, n, root, lo, hi, free, l, d, nl, pl, tg, fl, id, v, ST.nd(K, nl, id))
138
139def setp_same(-K: Data, +nl: List<&2, M.Node<K>>, +i: Nat, +v: Nat, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, 1n+i) == M.N{c, a, b, q, k} : M.Node<K>}, +hi: {Nat.is_lt(i, SC.length(M.Node<K>, nl)) == True{} : Bool}) -> {ST.nd(K, setp(K, nl, 1n+i, v), 1n+i) == M.N{c, a, b, v, k} : M.Node<K>}:
140  %Equal.sym(M.Node<K>, ST.nd(K, nl, 1n+i), M.N{c, a, b, q, k}, hx) : {ST.nd(K, setp_n(K, nl, 1n+i, v, _), 1n+i) == M.N{c, a, b, v, k} : M.Node<K>}
141  FR.nd_wr_same(K, nl, i, M.N{c, a, b, v, k}, hi)
142
143def setp_n_len(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +x: M.Node<K>) -> {SC.length(M.Node<K>, setp_n(K, nl, id, v, x)) == SC.length(M.Node<K>, nl) : Nat}:
144  match x:
145    case M.Free{f}:
146      {==}
147    case M.N{+c, +a, +b, +q, +k}:
148      FR.len_wr(K, nl, id, M.N{c, a, b, v, k})
149
150def setp_len(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> {SC.length(M.Node<K>, setp(K, nl, id, v)) == SC.length(M.Node<K>, nl) : Nat}:
151  setp_n_len(K, nl, id, v, ST.nd(K, nl, id))
152
153def setp_n_agr(~K: Data, ~cmp: K -> K -> Cmp, ~o: O.Order(~K, ~cmp), +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +x: M.Node<K>, +hn: {NL.memn(id, xs) == False{} : Bool}) -> {AG.agr(~K, ~cmp, xs, nl, setp_n(K, nl, id, v, x)) == True{} : Bool}:
154  match x:
155    case M.Free{f}:
156      AG.agr_refl(~K, ~cmp, ~o, xs, nl)
157    case M.N{+c, +a, +b, +q, +k}:
158      AG.agr_wr(~K, ~cmp, ~o, xs, nl, id, M.N{c, a, b, v, k}, hn)
159
160# agreement off the written id
161def setp_agr(~K: Data, ~cmp: K -> K -> Cmp, ~o: O.Order(~K, ~cmp), +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +hn: {NL.memn(id, xs) == False{} : Bool}) -> {AG.agr(~K, ~cmp, xs, nl, setp(K, nl, id, v)) == True{} : Bool}:
162  setp_n_agr(~K, ~cmp, ~o, xs, nl, id, v, ST.nd(K, nl, id), hn)
163
164# ---- red ----
165
166def setc_n(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, x: M.Node<K>) -> List<&2, M.Node<K>>:
167  match x:
168    case M.Free{f}:
169      nl
170    case M.N{+c, +a, +b, +q, +k}:
171      PR.wr_nl(K, nl, id, M.N{v, a, b, q, k})
172
173def setc(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool) -> List<&2, M.Node<K>>:
174  setc_n(K, nl, id, v, ST.nd(K, nl, id))
175
176def set_red_node_m(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, +n: Nat, +root: Nat, +lo: Nat, +hi: Nat, +free: Nat, +l: Nat, +d: Nat, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +tg: ST.Tr, +fl: List<&2, Nat>, +id: Nat, +v: Bool, +x: M.Node<K>) -> {MI.set_red_node(~K, ~V, ~cmp, ST.SH{n, root, lo, hi, free, l, d, nl, pl, tg, fl}, id, v, x) == ST.SH{n, root, lo, hi, free, l, d, setc_n(K, nl, id, v, x), pl, tg, fl} : ST.Sh<K, V>}:
177  match x:
178    case M.Free{f}:
179      {==}
180    case M.N{c, a, b, q, k}:
181      {==}
182
183def set_red_m(~K: Data, ~V: Data, ~cmp: K -> K -> Cmp, +n: Nat, +root: Nat, +lo: Nat, +hi: Nat, +free: Nat, +l: Nat, +d: Nat, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +tg: ST.Tr, +fl: List<&2, Nat>, +id: Nat, +v: Bool) -> {MI.set_red(~K, ~V, ~cmp, ST.SH{n, root, lo, hi, free, l, d, nl, pl, tg, fl}, id, v) == ST.SH{n, root, lo, hi, free, l, d, setc(K, nl, id, v), pl, tg, fl} : ST.Sh<K, V>}:
184  set_red_node_m(~K, ~V, ~cmp, n, root, lo, hi, free, l, d, nl, pl, tg, fl, id, v, ST.nd(K, nl, id))
185
186def setc_same(-K: Data, +nl: List<&2, M.Node<K>>, +i: Nat, +v: Bool, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, 1n+i) == M.N{c, a, b, q, k} : M.Node<K>}, +hi: {Nat.is_lt(i, SC.length(M.Node<K>, nl)) == True{} : Bool}) -> {ST.nd(K, setc(K, nl, 1n+i, v), 1n+i) == M.N{v, a, b, q, k} : M.Node<K>}:
187  %Equal.sym(M.Node<K>, ST.nd(K, nl, 1n+i), M.N{c, a, b, q, k}, hx) : {ST.nd(K, setc_n(K, nl, 1n+i, v, _), 1n+i) == M.N{v, a, b, q, k} : M.Node<K>}
188  FR.nd_wr_same(K, nl, i, M.N{v, a, b, q, k}, hi)
189
190def setc_n_len(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, +x: M.Node<K>) -> {SC.length(M.Node<K>, setc_n(K, nl, id, v, x)) == SC.length(M.Node<K>, nl) : Nat}:
191  match x:
192    case M.Free{f}:
193      {==}
194    case M.N{+c, +a, +b, +q, +k}:
195      FR.len_wr(K, nl, id, M.N{v, a, b, q, k})
196
197def setc_len(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool) -> {SC.length(M.Node<K>, setc(K, nl, id, v)) == SC.length(M.Node<K>, nl) : Nat}:
198  setc_n_len(K, nl, id, v, ST.nd(K, nl, id))
199
200def setc_n_agr(~K: Data, ~cmp: K -> K -> Cmp, ~o: O.Order(~K, ~cmp), +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, +x: M.Node<K>, +hn: {NL.memn(id, xs) == False{} : Bool}) -> {AG.agr(~K, ~cmp, xs, nl, setc_n(K, nl, id, v, x)) == True{} : Bool}:
201  match x:
202    case M.Free{f}:
203      AG.agr_refl(~K, ~cmp, ~o, xs, nl)
204    case M.N{+c, +a, +b, +q, +k}:
205      AG.agr_wr(~K, ~cmp, ~o, xs, nl, id, M.N{v, a, b, q, k}, hn)
206
207# agreement off the written id
208def setc_agr(~K: Data, ~cmp: K -> K -> Cmp, ~o: O.Order(~K, ~cmp), +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, +hn: {NL.memn(id, xs) == False{} : Bool}) -> {AG.agr(~K, ~cmp, xs, nl, setc(K, nl, id, v)) == True{} : Bool}:
209  setc_n_agr(~K, ~cmp, ~o, xs, nl, id, v, ST.nd(K, nl, id), hn)
210
211# ---- every id's node after a setter ----
212
213def fn_c(-K: Data, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +e: {M.Free{0n} == M.N{c, a, b, q, k} : M.Node<K>}) -> Empty:
214  L.true_false(L.subst(M.Node<K>, z => {ST.is_free(K, M.Free{0n}, 0n) == ST.is_free(K, z, 0n) : Bool}, M.Free{0n}, M.N{c, a, b, q, k}, e, {==}))
215
216def nr_c(-K: Data, +nl: List<&2, M.Node<K>>, +i: Nat, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, 1n+i) == M.N{c, a, b, q, k} : M.Node<K>}, +t: Bool, +ht: {Nat.is_lt(i, SC.length(M.Node<K>, nl)) == t : Bool}) -> {t == True{} : Bool}:
217  match t:
218    case True{}:
219      {==}
220    case False{}:
221      +e = Equal.trans(M.Node<K>, M.Free{0n}, ST.nd(K, nl, 1n+i), M.N{c, a, b, q, k}, Equal.sym(M.Node<K>, ST.nd(K, nl, 1n+i), M.Free{0n}, PR.nth_hi(M.Node<K>, nl, i, M.Free{0n}, ht)), hx)
222      Empty.absurd({False{} == True{} : Bool}, fn_c(K, c, a, b, q, k, e))
223
224def nd_n_range(-K: Data, +nl: List<&2, M.Node<K>>, +i: Nat, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, 1n+i) == M.N{c, a, b, q, k} : M.Node<K>}) -> {Nat.is_lt(i, SC.length(M.Node<K>, nl)) == True{} : Bool}:
225  nr_c(K, nl, i, c, a, b, q, k, hx, Nat.is_lt(i, SC.length(M.Node<K>, nl)), {==})
226
227def modl(-K: Data, x: M.Node<K>, +v: Nat) -> M.Node<K>:
228  match x:
229    case M.Free{+f}:
230      M.Free{f}
231    case M.N{+c, +a, +b, +q, +k}:
232      M.N{c, v, b, q, k}
233
234def wsame_l(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, id) == M.N{c, a, b, q, k} : M.Node<K>}) -> {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, v, b, q, k}), id) == M.N{c, v, b, q, k} : M.Node<K>}:
235  match id:
236    case 0n:
237      Empty.absurd({ST.nd(K, PR.wr_nl(K, nl, 0n, M.N{c, v, b, q, k}), 0n) == M.N{c, v, b, q, k} : M.Node<K>}, fn_c(K, c, a, b, q, k, hx))
238    case 1n+i:
239      FR.nd_wr_same(K, nl, i, M.N{c, v, b, q, k}, nd_n_range(K, nl, i, c, a, b, q, k, hx))
240
241def ndl_c(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat, +x: M.Node<K>, +hx: {ST.nd(K, nl, id) == x : M.Node<K>}, +e: Bool, +he: {Nat.is_eq(id, j) == e : Bool}) -> {ST.nd(K, setl_n(K, nl, id, v, x), j) == ST.pk(M.Node<K>, e, modl(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)) : M.Node<K>}:
242  match x e:
243    case M.Free{f} True{}:
244      +ej = N.eq_from_is_eq(id, j, he)
245      %Equal.sym(Nat, j, id, Equal.sym(Nat, id, j, ej)) : {ST.nd(K, nl, _) == modl(K, ST.nd(K, nl, _), v) : M.Node<K>}
246      %Equal.sym(M.Node<K>, ST.nd(K, nl, id), M.Free{f}, hx) : {_ == modl(K, _, v) : M.Node<K>}
247      {==}
248    case M.Free{f} False{}:
249      {==}
250    case M.N{+c, +a, +b, +q, +k} True{}:
251      +ej = N.eq_from_is_eq(id, j, he)
252      %Equal.sym(Nat, j, id, Equal.sym(Nat, id, j, ej)) : {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, v, b, q, k}), _) == modl(K, ST.nd(K, nl, _), v) : M.Node<K>}
253      %Equal.sym(M.Node<K>, ST.nd(K, nl, id), M.N{c, a, b, q, k}, hx) : {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, v, b, q, k}), id) == modl(K, _, v) : M.Node<K>}
254      wsame_l(K, nl, id, v, c, a, b, q, k, hx)
255    case M.N{+c, +a, +b, +q, +k} False{}:
256      FR.nd_wr_other(K, nl, id, M.N{c, v, b, q, k}, j, he)
257
258# the node at j after setting id: modified when j is id
259def ndl(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat) -> {ST.nd(K, setl(K, nl, id, v), j) == ST.pk(M.Node<K>, Nat.is_eq(id, j), modl(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)) : M.Node<K>}:
260  ndl_c(K, nl, id, v, j, ST.nd(K, nl, id), {==}, Nat.is_eq(id, j), {==})
261
262def modr(-K: Data, x: M.Node<K>, +v: Nat) -> M.Node<K>:
263  match x:
264    case M.Free{+f}:
265      M.Free{f}
266    case M.N{+c, +a, +b, +q, +k}:
267      M.N{c, a, v, q, k}
268
269def wsame_r(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, id) == M.N{c, a, b, q, k} : M.Node<K>}) -> {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, a, v, q, k}), id) == M.N{c, a, v, q, k} : M.Node<K>}:
270  match id:
271    case 0n:
272      Empty.absurd({ST.nd(K, PR.wr_nl(K, nl, 0n, M.N{c, a, v, q, k}), 0n) == M.N{c, a, v, q, k} : M.Node<K>}, fn_c(K, c, a, b, q, k, hx))
273    case 1n+i:
274      FR.nd_wr_same(K, nl, i, M.N{c, a, v, q, k}, nd_n_range(K, nl, i, c, a, b, q, k, hx))
275
276def ndr_c(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat, +x: M.Node<K>, +hx: {ST.nd(K, nl, id) == x : M.Node<K>}, +e: Bool, +he: {Nat.is_eq(id, j) == e : Bool}) -> {ST.nd(K, setr_n(K, nl, id, v, x), j) == ST.pk(M.Node<K>, e, modr(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)) : M.Node<K>}:
277  match x e:
278    case M.Free{f} True{}:
279      +ej = N.eq_from_is_eq(id, j, he)
280      %Equal.sym(Nat, j, id, Equal.sym(Nat, id, j, ej)) : {ST.nd(K, nl, _) == modr(K, ST.nd(K, nl, _), v) : M.Node<K>}
281      %Equal.sym(M.Node<K>, ST.nd(K, nl, id), M.Free{f}, hx) : {_ == modr(K, _, v) : M.Node<K>}
282      {==}
283    case M.Free{f} False{}:
284      {==}
285    case M.N{+c, +a, +b, +q, +k} True{}:
286      +ej = N.eq_from_is_eq(id, j, he)
287      %Equal.sym(Nat, j, id, Equal.sym(Nat, id, j, ej)) : {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, a, v, q, k}), _) == modr(K, ST.nd(K, nl, _), v) : M.Node<K>}
288      %Equal.sym(M.Node<K>, ST.nd(K, nl, id), M.N{c, a, b, q, k}, hx) : {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, a, v, q, k}), id) == modr(K, _, v) : M.Node<K>}
289      wsame_r(K, nl, id, v, c, a, b, q, k, hx)
290    case M.N{+c, +a, +b, +q, +k} False{}:
291      FR.nd_wr_other(K, nl, id, M.N{c, a, v, q, k}, j, he)
292
293# the node at j after setting id: modified when j is id
294def ndr(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat) -> {ST.nd(K, setr(K, nl, id, v), j) == ST.pk(M.Node<K>, Nat.is_eq(id, j), modr(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)) : M.Node<K>}:
295  ndr_c(K, nl, id, v, j, ST.nd(K, nl, id), {==}, Nat.is_eq(id, j), {==})
296
297def modp(-K: Data, x: M.Node<K>, +v: Nat) -> M.Node<K>:
298  match x:
299    case M.Free{+f}:
300      M.Free{f}
301    case M.N{+c, +a, +b, +q, +k}:
302      M.N{c, a, b, v, k}
303
304def wsame_p(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, id) == M.N{c, a, b, q, k} : M.Node<K>}) -> {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, a, b, v, k}), id) == M.N{c, a, b, v, k} : M.Node<K>}:
305  match id:
306    case 0n:
307      Empty.absurd({ST.nd(K, PR.wr_nl(K, nl, 0n, M.N{c, a, b, v, k}), 0n) == M.N{c, a, b, v, k} : M.Node<K>}, fn_c(K, c, a, b, q, k, hx))
308    case 1n+i:
309      FR.nd_wr_same(K, nl, i, M.N{c, a, b, v, k}, nd_n_range(K, nl, i, c, a, b, q, k, hx))
310
311def ndp_c(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat, +x: M.Node<K>, +hx: {ST.nd(K, nl, id) == x : M.Node<K>}, +e: Bool, +he: {Nat.is_eq(id, j) == e : Bool}) -> {ST.nd(K, setp_n(K, nl, id, v, x), j) == ST.pk(M.Node<K>, e, modp(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)) : M.Node<K>}:
312  match x e:
313    case M.Free{f} True{}:
314      +ej = N.eq_from_is_eq(id, j, he)
315      %Equal.sym(Nat, j, id, Equal.sym(Nat, id, j, ej)) : {ST.nd(K, nl, _) == modp(K, ST.nd(K, nl, _), v) : M.Node<K>}
316      %Equal.sym(M.Node<K>, ST.nd(K, nl, id), M.Free{f}, hx) : {_ == modp(K, _, v) : M.Node<K>}
317      {==}
318    case M.Free{f} False{}:
319      {==}
320    case M.N{+c, +a, +b, +q, +k} True{}:
321      +ej = N.eq_from_is_eq(id, j, he)
322      %Equal.sym(Nat, j, id, Equal.sym(Nat, id, j, ej)) : {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, a, b, v, k}), _) == modp(K, ST.nd(K, nl, _), v) : M.Node<K>}
323      %Equal.sym(M.Node<K>, ST.nd(K, nl, id), M.N{c, a, b, q, k}, hx) : {ST.nd(K, PR.wr_nl(K, nl, id, M.N{c, a, b, v, k}), id) == modp(K, _, v) : M.Node<K>}
324      wsame_p(K, nl, id, v, c, a, b, q, k, hx)
325    case M.N{+c, +a, +b, +q, +k} False{}:
326      FR.nd_wr_other(K, nl, id, M.N{c, a, b, v, k}, j, he)
327
328# the node at j after setting id: modified when j is id
329def ndp(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat) -> {ST.nd(K, setp(K, nl, id, v), j) == ST.pk(M.Node<K>, Nat.is_eq(id, j), modp(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)) : M.Node<K>}:
330  ndp_c(K, nl, id, v, j, ST.nd(K, nl, id), {==}, Nat.is_eq(id, j), {==})
331
332def modc(-K: Data, x: M.Node<K>, +v: Bool) -> M.Node<K>:
333  match x:
334    case M.Free{+f}:
335      M.Free{f}
336    case M.N{+c, +a, +b, +q, +k}:
337      M.N{v, a, b, q, k}
338
339def wsame_c(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, +c: Bool, +a: Nat, +b: Nat, +q: Nat, +k: K, +hx: {ST.nd(K, nl, id) == M.N{c, a, b, q, k} : M.Node<K>}) -> {ST.nd(K, PR.wr_nl(K, nl, id, M.N{v, a, b, q, k}), id) == M.N{v, a, b, q, k} : M.Node<K>}:
340  match id:
341    case 0n:
342      Empty.absurd({ST.nd(K, PR.wr_nl(K, nl, 0n, M.N{v, a, b, q, k}), 0n) == M.N{v, a, b, q, k} : M.Node<K>}, fn_c(K, c, a, b, q, k, hx))
343    case 1n+i:
344      FR.nd_wr_same(K, nl, i, M.N{v, a, b, q, k}, nd_n_range(K, nl, i, c, a, b, q, k, hx))
345
346def ndc_c(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, +j: Nat, +x: M.Node<K>, +hx: {ST.nd(K, nl, id) == x : M.Node<K>}, +e: Bool, +he: {Nat.is_eq(id, j) == e : Bool}) -> {ST.nd(K, setc_n(K, nl, id, v, x), j) == ST.pk(M.Node<K>, e, modc(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)) : M.Node<K>}:
347  match x e:
348    case M.Free{f} True{}:
349      +ej = N.eq_from_is_eq(id, j, he)
350      %Equal.sym(Nat, j, id, Equal.sym(Nat, id, j, ej)) : {ST.nd(K, nl, _) == modc(K, ST.nd(K, nl, _), v) : M.Node<K>}
351      %Equal.sym(M.Node<K>, ST.nd(K, nl, id), M.Free{f}, hx) : {_ == modc(K, _, v) : M.Node<K>}
352      {==}
353    case M.Free{f} False{}:
354      {==}
355    case M.N{+c, +a, +b, +q, +k} True{}:
356      +ej = N.eq_from_is_eq(id, j, he)
357      %Equal.sym(Nat, j, id, Equal.sym(Nat, id, j, ej)) : {ST.nd(K, PR.wr_nl(K, nl, id, M.N{v, a, b, q, k}), _) == modc(K, ST.nd(K, nl, _), v) : M.Node<K>}
358      %Equal.sym(M.Node<K>, ST.nd(K, nl, id), M.N{c, a, b, q, k}, hx) : {ST.nd(K, PR.wr_nl(K, nl, id, M.N{v, a, b, q, k}), id) == modc(K, _, v) : M.Node<K>}
359      wsame_c(K, nl, id, v, c, a, b, q, k, hx)
360    case M.N{+c, +a, +b, +q, +k} False{}:
361      FR.nd_wr_other(K, nl, id, M.N{v, a, b, q, k}, j, he)
362
363# the node at j after setting id: modified when j is id
364def ndc(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, +j: Nat) -> {ST.nd(K, setc(K, nl, id, v), j) == ST.pk(M.Node<K>, Nat.is_eq(id, j), modc(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)) : M.Node<K>}:
365  ndc_c(K, nl, id, v, j, ST.nd(K, nl, id), {==}, Nat.is_eq(id, j), {==})
366
367# ---- what setters keep everywhere ----
368
369
370def ent_modl(-K: Data, -V: Data, +x: M.Node<K>, +v: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, modl(K, x, v), m) == ST.ent(K, V, x, m) : Maybe<&2, M.Entry<K, V>>}:
371  match x m:
372    case M.Free{f} +m:
373      {==}
374    case M.N{c, a, b, q, k} None{}:
375      {==}
376    case M.N{c, a, b, q, k} Some{w}:
377      {==}
378
379def free_modl(-K: Data, +x: M.Node<K>, +v: Nat, +q: Nat) -> {ST.is_free(K, modl(K, x, v), q) == ST.is_free(K, x, q) : Bool}:
380  match x:
381    case M.Free{f}:
382      {==}
383    case M.N{c, a, b, q2, k}:
384      {==}
385
386def ent_pkl(-K: Data, -V: Data, +e: Bool, +x: M.Node<K>, +v: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, ST.pk(M.Node<K>, e, modl(K, x, v), x), m) == ST.ent(K, V, x, m) : Maybe<&2, M.Entry<K, V>>}:
387  match e:
388    case True{}:
389      ent_modl(K, V, x, v, m)
390    case False{}:
391      {==}
392
393def free_pkl(-K: Data, +e: Bool, +x: M.Node<K>, +v: Nat, +q: Nat) -> {ST.is_free(K, ST.pk(M.Node<K>, e, modl(K, x, v), x), q) == ST.is_free(K, x, q) : Bool}:
394  match e:
395    case True{}:
396      free_modl(K, x, v, q)
397    case False{}:
398      {==}
399
400def ent_setl(-K: Data, -V: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, ST.nd(K, setl(K, nl, id, v), j), m) == ST.ent(K, V, ST.nd(K, nl, j), m) : Maybe<&2, M.Entry<K, V>>}:
401  %Equal.sym(M.Node<K>, ST.nd(K, setl(K, nl, id, v), j), ST.pk(M.Node<K>, Nat.is_eq(id, j), modl(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)), ndl(K, nl, id, v, j)) : {ST.ent(K, V, _, m) == ST.ent(K, V, ST.nd(K, nl, j), m) : Maybe<&2, M.Entry<K, V>>}
402  ent_pkl(K, V, Nat.is_eq(id, j), ST.nd(K, nl, j), v, m)
403
404# a setter keeps every entry
405def ents_setl(~K: Data, ~V: Data, +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +id: Nat, +v: Nat) -> {ST.ents(~K, ~V, xs, setl(K, nl, id, v), pl) == ST.ents(~K, ~V, xs, nl, pl) : List<&2, M.Entry<K, V>>}:
406  match xs:
407    case Nil{}:
408      {==}
409    case Con{+j, +t}:
410      %Equal.sym(Maybe<&2, M.Entry<K, V>>, ST.ent(K, V, ST.nd(K, setl(K, nl, id, v), j), ST.pv(V, pl, j)), ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), ent_setl(K, V, nl, id, v, j, ST.pv(V, pl, j))) : {ST.cons_m(M.Entry<K, V>, _, ST.ents(~K, ~V, t, setl(K, nl, id, v), pl)) == ST.ents(~K, ~V, Con{j, t}, nl, pl) : List<&2, M.Entry<K, V>>}
411      %Equal.sym(List<&2, M.Entry<K, V>>, ST.ents(~K, ~V, t, setl(K, nl, id, v), pl), ST.ents(~K, ~V, t, nl, pl), ents_setl(~K, ~V, t, nl, pl, id, v)) : {ST.cons_m(M.Entry<K, V>, ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), _) == ST.ents(~K, ~V, Con{j, t}, nl, pl) : List<&2, M.Entry<K, V>>}
412      {==}
413
414def oks_setl(~K: Data, ~V: Data, +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +id: Nat, +v: Nat) -> {EN.oks(~K, ~V, xs, setl(K, nl, id, v), pl) == EN.oks(~K, ~V, xs, nl, pl) : Bool}:
415  match xs:
416    case Nil{}:
417      {==}
418    case Con{+j, +t}:
419      %Equal.sym(Maybe<&2, M.Entry<K, V>>, ST.ent(K, V, ST.nd(K, setl(K, nl, id, v), j), ST.pv(V, pl, j)), ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), ent_setl(K, V, nl, id, v, j, ST.pv(V, pl, j))) : {Bool.and(S.is_some(M.Entry<K, V>, _), EN.oks(~K, ~V, t, setl(K, nl, id, v), pl)) == EN.oks(~K, ~V, Con{j, t}, nl, pl) : Bool}
420      %Equal.sym(Bool, EN.oks(~K, ~V, t, setl(K, nl, id, v), pl), EN.oks(~K, ~V, t, nl, pl), oks_setl(~K, ~V, t, nl, pl, id, v)) : {Bool.and(S.is_some(M.Entry<K, V>, ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j))), _) == EN.oks(~K, ~V, Con{j, t}, nl, pl) : Bool}
421      {==}
422
423# a setter keeps the free chain
424def fll_setl(~K: Data, +fl: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> {ST.fll(~K, setl(K, nl, id, v), fl) == ST.fll(~K, nl, fl) : Bool}:
425  match fl:
426    case Nil{}:
427      {==}
428    case Con{+f, +t}:
429      %Equal.sym(M.Node<K>, ST.nd(K, setl(K, nl, id, v), f), ST.pk(M.Node<K>, Nat.is_eq(id, f), modl(K, ST.nd(K, nl, f), v), ST.nd(K, nl, f)), ndl(K, nl, id, v, f)) : {Bool.and(ST.is_free(K, _, ST.fst0(t)), ST.fll(~K, setl(K, nl, id, v), t)) == ST.fll(~K, nl, Con{f, t}) : Bool}
430      %Equal.sym(Bool, ST.is_free(K, ST.pk(M.Node<K>, Nat.is_eq(id, f), modl(K, ST.nd(K, nl, f), v), ST.nd(K, nl, f)), ST.fst0(t)), ST.is_free(K, ST.nd(K, nl, f), ST.fst0(t)), free_pkl(K, Nat.is_eq(id, f), ST.nd(K, nl, f), v, ST.fst0(t))) : {Bool.and(_, ST.fll(~K, setl(K, nl, id, v), t)) == ST.fll(~K, nl, Con{f, t}) : Bool}
431      %Equal.sym(Bool, ST.fll(~K, setl(K, nl, id, v), t), ST.fll(~K, nl, t), fll_setl(~K, t, nl, id, v)) : {Bool.and(ST.is_free(K, ST.nd(K, nl, f), ST.fst0(t)), _) == ST.fll(~K, nl, Con{f, t}) : Bool}
432      {==}
433
434def ent_modr(-K: Data, -V: Data, +x: M.Node<K>, +v: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, modr(K, x, v), m) == ST.ent(K, V, x, m) : Maybe<&2, M.Entry<K, V>>}:
435  match x m:
436    case M.Free{f} +m:
437      {==}
438    case M.N{c, a, b, q, k} None{}:
439      {==}
440    case M.N{c, a, b, q, k} Some{w}:
441      {==}
442
443def free_modr(-K: Data, +x: M.Node<K>, +v: Nat, +q: Nat) -> {ST.is_free(K, modr(K, x, v), q) == ST.is_free(K, x, q) : Bool}:
444  match x:
445    case M.Free{f}:
446      {==}
447    case M.N{c, a, b, q2, k}:
448      {==}
449
450def ent_pkr(-K: Data, -V: Data, +e: Bool, +x: M.Node<K>, +v: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, ST.pk(M.Node<K>, e, modr(K, x, v), x), m) == ST.ent(K, V, x, m) : Maybe<&2, M.Entry<K, V>>}:
451  match e:
452    case True{}:
453      ent_modr(K, V, x, v, m)
454    case False{}:
455      {==}
456
457def free_pkr(-K: Data, +e: Bool, +x: M.Node<K>, +v: Nat, +q: Nat) -> {ST.is_free(K, ST.pk(M.Node<K>, e, modr(K, x, v), x), q) == ST.is_free(K, x, q) : Bool}:
458  match e:
459    case True{}:
460      free_modr(K, x, v, q)
461    case False{}:
462      {==}
463
464def ent_setr(-K: Data, -V: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, ST.nd(K, setr(K, nl, id, v), j), m) == ST.ent(K, V, ST.nd(K, nl, j), m) : Maybe<&2, M.Entry<K, V>>}:
465  %Equal.sym(M.Node<K>, ST.nd(K, setr(K, nl, id, v), j), ST.pk(M.Node<K>, Nat.is_eq(id, j), modr(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)), ndr(K, nl, id, v, j)) : {ST.ent(K, V, _, m) == ST.ent(K, V, ST.nd(K, nl, j), m) : Maybe<&2, M.Entry<K, V>>}
466  ent_pkr(K, V, Nat.is_eq(id, j), ST.nd(K, nl, j), v, m)
467
468# a setter keeps every entry
469def ents_setr(~K: Data, ~V: Data, +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +id: Nat, +v: Nat) -> {ST.ents(~K, ~V, xs, setr(K, nl, id, v), pl) == ST.ents(~K, ~V, xs, nl, pl) : List<&2, M.Entry<K, V>>}:
470  match xs:
471    case Nil{}:
472      {==}
473    case Con{+j, +t}:
474      %Equal.sym(Maybe<&2, M.Entry<K, V>>, ST.ent(K, V, ST.nd(K, setr(K, nl, id, v), j), ST.pv(V, pl, j)), ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), ent_setr(K, V, nl, id, v, j, ST.pv(V, pl, j))) : {ST.cons_m(M.Entry<K, V>, _, ST.ents(~K, ~V, t, setr(K, nl, id, v), pl)) == ST.ents(~K, ~V, Con{j, t}, nl, pl) : List<&2, M.Entry<K, V>>}
475      %Equal.sym(List<&2, M.Entry<K, V>>, ST.ents(~K, ~V, t, setr(K, nl, id, v), pl), ST.ents(~K, ~V, t, nl, pl), ents_setr(~K, ~V, t, nl, pl, id, v)) : {ST.cons_m(M.Entry<K, V>, ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), _) == ST.ents(~K, ~V, Con{j, t}, nl, pl) : List<&2, M.Entry<K, V>>}
476      {==}
477
478def oks_setr(~K: Data, ~V: Data, +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +id: Nat, +v: Nat) -> {EN.oks(~K, ~V, xs, setr(K, nl, id, v), pl) == EN.oks(~K, ~V, xs, nl, pl) : Bool}:
479  match xs:
480    case Nil{}:
481      {==}
482    case Con{+j, +t}:
483      %Equal.sym(Maybe<&2, M.Entry<K, V>>, ST.ent(K, V, ST.nd(K, setr(K, nl, id, v), j), ST.pv(V, pl, j)), ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), ent_setr(K, V, nl, id, v, j, ST.pv(V, pl, j))) : {Bool.and(S.is_some(M.Entry<K, V>, _), EN.oks(~K, ~V, t, setr(K, nl, id, v), pl)) == EN.oks(~K, ~V, Con{j, t}, nl, pl) : Bool}
484      %Equal.sym(Bool, EN.oks(~K, ~V, t, setr(K, nl, id, v), pl), EN.oks(~K, ~V, t, nl, pl), oks_setr(~K, ~V, t, nl, pl, id, v)) : {Bool.and(S.is_some(M.Entry<K, V>, ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j))), _) == EN.oks(~K, ~V, Con{j, t}, nl, pl) : Bool}
485      {==}
486
487# a setter keeps the free chain
488def fll_setr(~K: Data, +fl: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> {ST.fll(~K, setr(K, nl, id, v), fl) == ST.fll(~K, nl, fl) : Bool}:
489  match fl:
490    case Nil{}:
491      {==}
492    case Con{+f, +t}:
493      %Equal.sym(M.Node<K>, ST.nd(K, setr(K, nl, id, v), f), ST.pk(M.Node<K>, Nat.is_eq(id, f), modr(K, ST.nd(K, nl, f), v), ST.nd(K, nl, f)), ndr(K, nl, id, v, f)) : {Bool.and(ST.is_free(K, _, ST.fst0(t)), ST.fll(~K, setr(K, nl, id, v), t)) == ST.fll(~K, nl, Con{f, t}) : Bool}
494      %Equal.sym(Bool, ST.is_free(K, ST.pk(M.Node<K>, Nat.is_eq(id, f), modr(K, ST.nd(K, nl, f), v), ST.nd(K, nl, f)), ST.fst0(t)), ST.is_free(K, ST.nd(K, nl, f), ST.fst0(t)), free_pkr(K, Nat.is_eq(id, f), ST.nd(K, nl, f), v, ST.fst0(t))) : {Bool.and(_, ST.fll(~K, setr(K, nl, id, v), t)) == ST.fll(~K, nl, Con{f, t}) : Bool}
495      %Equal.sym(Bool, ST.fll(~K, setr(K, nl, id, v), t), ST.fll(~K, nl, t), fll_setr(~K, t, nl, id, v)) : {Bool.and(ST.is_free(K, ST.nd(K, nl, f), ST.fst0(t)), _) == ST.fll(~K, nl, Con{f, t}) : Bool}
496      {==}
497
498def ent_modp(-K: Data, -V: Data, +x: M.Node<K>, +v: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, modp(K, x, v), m) == ST.ent(K, V, x, m) : Maybe<&2, M.Entry<K, V>>}:
499  match x m:
500    case M.Free{f} +m:
501      {==}
502    case M.N{c, a, b, q, k} None{}:
503      {==}
504    case M.N{c, a, b, q, k} Some{w}:
505      {==}
506
507def free_modp(-K: Data, +x: M.Node<K>, +v: Nat, +q: Nat) -> {ST.is_free(K, modp(K, x, v), q) == ST.is_free(K, x, q) : Bool}:
508  match x:
509    case M.Free{f}:
510      {==}
511    case M.N{c, a, b, q2, k}:
512      {==}
513
514def ent_pkp(-K: Data, -V: Data, +e: Bool, +x: M.Node<K>, +v: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, ST.pk(M.Node<K>, e, modp(K, x, v), x), m) == ST.ent(K, V, x, m) : Maybe<&2, M.Entry<K, V>>}:
515  match e:
516    case True{}:
517      ent_modp(K, V, x, v, m)
518    case False{}:
519      {==}
520
521def free_pkp(-K: Data, +e: Bool, +x: M.Node<K>, +v: Nat, +q: Nat) -> {ST.is_free(K, ST.pk(M.Node<K>, e, modp(K, x, v), x), q) == ST.is_free(K, x, q) : Bool}:
522  match e:
523    case True{}:
524      free_modp(K, x, v, q)
525    case False{}:
526      {==}
527
528def ent_setp(-K: Data, -V: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, ST.nd(K, setp(K, nl, id, v), j), m) == ST.ent(K, V, ST.nd(K, nl, j), m) : Maybe<&2, M.Entry<K, V>>}:
529  %Equal.sym(M.Node<K>, ST.nd(K, setp(K, nl, id, v), j), ST.pk(M.Node<K>, Nat.is_eq(id, j), modp(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)), ndp(K, nl, id, v, j)) : {ST.ent(K, V, _, m) == ST.ent(K, V, ST.nd(K, nl, j), m) : Maybe<&2, M.Entry<K, V>>}
530  ent_pkp(K, V, Nat.is_eq(id, j), ST.nd(K, nl, j), v, m)
531
532# a setter keeps every entry
533def ents_setp(~K: Data, ~V: Data, +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +id: Nat, +v: Nat) -> {ST.ents(~K, ~V, xs, setp(K, nl, id, v), pl) == ST.ents(~K, ~V, xs, nl, pl) : List<&2, M.Entry<K, V>>}:
534  match xs:
535    case Nil{}:
536      {==}
537    case Con{+j, +t}:
538      %Equal.sym(Maybe<&2, M.Entry<K, V>>, ST.ent(K, V, ST.nd(K, setp(K, nl, id, v), j), ST.pv(V, pl, j)), ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), ent_setp(K, V, nl, id, v, j, ST.pv(V, pl, j))) : {ST.cons_m(M.Entry<K, V>, _, ST.ents(~K, ~V, t, setp(K, nl, id, v), pl)) == ST.ents(~K, ~V, Con{j, t}, nl, pl) : List<&2, M.Entry<K, V>>}
539      %Equal.sym(List<&2, M.Entry<K, V>>, ST.ents(~K, ~V, t, setp(K, nl, id, v), pl), ST.ents(~K, ~V, t, nl, pl), ents_setp(~K, ~V, t, nl, pl, id, v)) : {ST.cons_m(M.Entry<K, V>, ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), _) == ST.ents(~K, ~V, Con{j, t}, nl, pl) : List<&2, M.Entry<K, V>>}
540      {==}
541
542def oks_setp(~K: Data, ~V: Data, +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +id: Nat, +v: Nat) -> {EN.oks(~K, ~V, xs, setp(K, nl, id, v), pl) == EN.oks(~K, ~V, xs, nl, pl) : Bool}:
543  match xs:
544    case Nil{}:
545      {==}
546    case Con{+j, +t}:
547      %Equal.sym(Maybe<&2, M.Entry<K, V>>, ST.ent(K, V, ST.nd(K, setp(K, nl, id, v), j), ST.pv(V, pl, j)), ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), ent_setp(K, V, nl, id, v, j, ST.pv(V, pl, j))) : {Bool.and(S.is_some(M.Entry<K, V>, _), EN.oks(~K, ~V, t, setp(K, nl, id, v), pl)) == EN.oks(~K, ~V, Con{j, t}, nl, pl) : Bool}
548      %Equal.sym(Bool, EN.oks(~K, ~V, t, setp(K, nl, id, v), pl), EN.oks(~K, ~V, t, nl, pl), oks_setp(~K, ~V, t, nl, pl, id, v)) : {Bool.and(S.is_some(M.Entry<K, V>, ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j))), _) == EN.oks(~K, ~V, Con{j, t}, nl, pl) : Bool}
549      {==}
550
551# a setter keeps the free chain
552def fll_setp(~K: Data, +fl: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat) -> {ST.fll(~K, setp(K, nl, id, v), fl) == ST.fll(~K, nl, fl) : Bool}:
553  match fl:
554    case Nil{}:
555      {==}
556    case Con{+f, +t}:
557      %Equal.sym(M.Node<K>, ST.nd(K, setp(K, nl, id, v), f), ST.pk(M.Node<K>, Nat.is_eq(id, f), modp(K, ST.nd(K, nl, f), v), ST.nd(K, nl, f)), ndp(K, nl, id, v, f)) : {Bool.and(ST.is_free(K, _, ST.fst0(t)), ST.fll(~K, setp(K, nl, id, v), t)) == ST.fll(~K, nl, Con{f, t}) : Bool}
558      %Equal.sym(Bool, ST.is_free(K, ST.pk(M.Node<K>, Nat.is_eq(id, f), modp(K, ST.nd(K, nl, f), v), ST.nd(K, nl, f)), ST.fst0(t)), ST.is_free(K, ST.nd(K, nl, f), ST.fst0(t)), free_pkp(K, Nat.is_eq(id, f), ST.nd(K, nl, f), v, ST.fst0(t))) : {Bool.and(_, ST.fll(~K, setp(K, nl, id, v), t)) == ST.fll(~K, nl, Con{f, t}) : Bool}
559      %Equal.sym(Bool, ST.fll(~K, setp(K, nl, id, v), t), ST.fll(~K, nl, t), fll_setp(~K, t, nl, id, v)) : {Bool.and(ST.is_free(K, ST.nd(K, nl, f), ST.fst0(t)), _) == ST.fll(~K, nl, Con{f, t}) : Bool}
560      {==}
561
562def ent_modc(-K: Data, -V: Data, +x: M.Node<K>, +v: Bool, +m: Maybe<&2, V>) -> {ST.ent(K, V, modc(K, x, v), m) == ST.ent(K, V, x, m) : Maybe<&2, M.Entry<K, V>>}:
563  match x m:
564    case M.Free{f} +m:
565      {==}
566    case M.N{c, a, b, q, k} None{}:
567      {==}
568    case M.N{c, a, b, q, k} Some{w}:
569      {==}
570
571def free_modc(-K: Data, +x: M.Node<K>, +v: Bool, +q: Nat) -> {ST.is_free(K, modc(K, x, v), q) == ST.is_free(K, x, q) : Bool}:
572  match x:
573    case M.Free{f}:
574      {==}
575    case M.N{c, a, b, q2, k}:
576      {==}
577
578def ent_pkc(-K: Data, -V: Data, +e: Bool, +x: M.Node<K>, +v: Bool, +m: Maybe<&2, V>) -> {ST.ent(K, V, ST.pk(M.Node<K>, e, modc(K, x, v), x), m) == ST.ent(K, V, x, m) : Maybe<&2, M.Entry<K, V>>}:
579  match e:
580    case True{}:
581      ent_modc(K, V, x, v, m)
582    case False{}:
583      {==}
584
585def free_pkc(-K: Data, +e: Bool, +x: M.Node<K>, +v: Bool, +q: Nat) -> {ST.is_free(K, ST.pk(M.Node<K>, e, modc(K, x, v), x), q) == ST.is_free(K, x, q) : Bool}:
586  match e:
587    case True{}:
588      free_modc(K, x, v, q)
589    case False{}:
590      {==}
591
592def ent_setc(-K: Data, -V: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, +j: Nat, +m: Maybe<&2, V>) -> {ST.ent(K, V, ST.nd(K, setc(K, nl, id, v), j), m) == ST.ent(K, V, ST.nd(K, nl, j), m) : Maybe<&2, M.Entry<K, V>>}:
593  %Equal.sym(M.Node<K>, ST.nd(K, setc(K, nl, id, v), j), ST.pk(M.Node<K>, Nat.is_eq(id, j), modc(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)), ndc(K, nl, id, v, j)) : {ST.ent(K, V, _, m) == ST.ent(K, V, ST.nd(K, nl, j), m) : Maybe<&2, M.Entry<K, V>>}
594  ent_pkc(K, V, Nat.is_eq(id, j), ST.nd(K, nl, j), v, m)
595
596# a setter keeps every entry
597def ents_setc(~K: Data, ~V: Data, +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +id: Nat, +v: Bool) -> {ST.ents(~K, ~V, xs, setc(K, nl, id, v), pl) == ST.ents(~K, ~V, xs, nl, pl) : List<&2, M.Entry<K, V>>}:
598  match xs:
599    case Nil{}:
600      {==}
601    case Con{+j, +t}:
602      %Equal.sym(Maybe<&2, M.Entry<K, V>>, ST.ent(K, V, ST.nd(K, setc(K, nl, id, v), j), ST.pv(V, pl, j)), ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), ent_setc(K, V, nl, id, v, j, ST.pv(V, pl, j))) : {ST.cons_m(M.Entry<K, V>, _, ST.ents(~K, ~V, t, setc(K, nl, id, v), pl)) == ST.ents(~K, ~V, Con{j, t}, nl, pl) : List<&2, M.Entry<K, V>>}
603      %Equal.sym(List<&2, M.Entry<K, V>>, ST.ents(~K, ~V, t, setc(K, nl, id, v), pl), ST.ents(~K, ~V, t, nl, pl), ents_setc(~K, ~V, t, nl, pl, id, v)) : {ST.cons_m(M.Entry<K, V>, ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), _) == ST.ents(~K, ~V, Con{j, t}, nl, pl) : List<&2, M.Entry<K, V>>}
604      {==}
605
606def oks_setc(~K: Data, ~V: Data, +xs: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +pl: List<&2, Maybe<&2, V>>, +id: Nat, +v: Bool) -> {EN.oks(~K, ~V, xs, setc(K, nl, id, v), pl) == EN.oks(~K, ~V, xs, nl, pl) : Bool}:
607  match xs:
608    case Nil{}:
609      {==}
610    case Con{+j, +t}:
611      %Equal.sym(Maybe<&2, M.Entry<K, V>>, ST.ent(K, V, ST.nd(K, setc(K, nl, id, v), j), ST.pv(V, pl, j)), ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j)), ent_setc(K, V, nl, id, v, j, ST.pv(V, pl, j))) : {Bool.and(S.is_some(M.Entry<K, V>, _), EN.oks(~K, ~V, t, setc(K, nl, id, v), pl)) == EN.oks(~K, ~V, Con{j, t}, nl, pl) : Bool}
612      %Equal.sym(Bool, EN.oks(~K, ~V, t, setc(K, nl, id, v), pl), EN.oks(~K, ~V, t, nl, pl), oks_setc(~K, ~V, t, nl, pl, id, v)) : {Bool.and(S.is_some(M.Entry<K, V>, ST.ent(K, V, ST.nd(K, nl, j), ST.pv(V, pl, j))), _) == EN.oks(~K, ~V, Con{j, t}, nl, pl) : Bool}
613      {==}
614
615# a setter keeps the free chain
616def fll_setc(~K: Data, +fl: List<&2, Nat>, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool) -> {ST.fll(~K, setc(K, nl, id, v), fl) == ST.fll(~K, nl, fl) : Bool}:
617  match fl:
618    case Nil{}:
619      {==}
620    case Con{+f, +t}:
621      %Equal.sym(M.Node<K>, ST.nd(K, setc(K, nl, id, v), f), ST.pk(M.Node<K>, Nat.is_eq(id, f), modc(K, ST.nd(K, nl, f), v), ST.nd(K, nl, f)), ndc(K, nl, id, v, f)) : {Bool.and(ST.is_free(K, _, ST.fst0(t)), ST.fll(~K, setc(K, nl, id, v), t)) == ST.fll(~K, nl, Con{f, t}) : Bool}
622      %Equal.sym(Bool, ST.is_free(K, ST.pk(M.Node<K>, Nat.is_eq(id, f), modc(K, ST.nd(K, nl, f), v), ST.nd(K, nl, f)), ST.fst0(t)), ST.is_free(K, ST.nd(K, nl, f), ST.fst0(t)), free_pkc(K, Nat.is_eq(id, f), ST.nd(K, nl, f), v, ST.fst0(t))) : {Bool.and(_, ST.fll(~K, setc(K, nl, id, v), t)) == ST.fll(~K, nl, Con{f, t}) : Bool}
623      %Equal.sym(Bool, ST.fll(~K, setc(K, nl, id, v), t), ST.fll(~K, nl, t), fll_setc(~K, t, nl, id, v)) : {Bool.and(ST.is_free(K, ST.nd(K, nl, f), ST.fst0(t)), _) == ST.fll(~K, nl, Con{f, t}) : Bool}
624      {==}
625
626# ---- recolouring keeps every link ----
627
628
629def isn_modc(-K: Data, +x: M.Node<K>, +v: Bool, +a: Nat, +b: Nat, +q: Nat) -> {ST.is_node(K, modc(K, x, v), a, b, q) == ST.is_node(K, x, a, b, q) : Bool}:
630  match x:
631    case M.Free{f}:
632      {==}
633    case M.N{c, x1, x2, x3, k}:
634      {==}
635
636def isn_pkc(-K: Data, +e: Bool, +x: M.Node<K>, +v: Bool, +a: Nat, +b: Nat, +q: Nat) -> {ST.is_node(K, ST.pk(M.Node<K>, e, modc(K, x, v), x), a, b, q) == ST.is_node(K, x, a, b, q) : Bool}:
637  match e:
638    case True{}:
639      isn_modc(K, x, v, a, b, q)
640    case False{}:
641      {==}
642
643def isn_setc(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool, +j: Nat, +a: Nat, +b: Nat, +q: Nat) -> {ST.is_node(K, ST.nd(K, setc(K, nl, id, v), j), a, b, q) == ST.is_node(K, ST.nd(K, nl, j), a, b, q) : Bool}:
644  %Equal.sym(M.Node<K>, ST.nd(K, setc(K, nl, id, v), j), ST.pk(M.Node<K>, Nat.is_eq(id, j), modc(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)), ndc(K, nl, id, v, j)) : {ST.is_node(K, _, a, b, q) == ST.is_node(K, ST.nd(K, nl, j), a, b, q) : Bool}
645  isn_pkc(K, Nat.is_eq(id, j), ST.nd(K, nl, j), v, a, b, q)
646
647def rep_setc(~K: Data, +t: ST.Tr, +p: Nat, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool) -> {ST.rep(~K, t, p, setc(K, nl, id, v)) == ST.rep(~K, t, p, nl) : Bool}:
648  match t:
649    case ST.TE{}:
650      {==}
651    case ST.TN{+i, +l, +r}:
652      %Equal.sym(Bool, ST.is_node(K, ST.nd(K, setc(K, nl, id, v), i), ST.rid(l), ST.rid(r), p), ST.is_node(K, ST.nd(K, nl, i), ST.rid(l), ST.rid(r), p), isn_setc(K, nl, id, v, i, ST.rid(l), ST.rid(r), p)) : {Bool.and(Nat.is_lt(0n, i), Bool.and(_, Bool.and(ST.rep(~K, l, i, setc(K, nl, id, v)), ST.rep(~K, r, i, setc(K, nl, id, v))))) == ST.rep(~K, ST.TN{i, l, r}, p, nl) : Bool}
653      %Equal.sym(Bool, ST.rep(~K, l, i, setc(K, nl, id, v)), ST.rep(~K, l, i, nl), rep_setc(~K, l, i, nl, id, v)) : {Bool.and(Nat.is_lt(0n, i), Bool.and(ST.is_node(K, ST.nd(K, nl, i), ST.rid(l), ST.rid(r), p), Bool.and(_, ST.rep(~K, r, i, setc(K, nl, id, v))))) == ST.rep(~K, ST.TN{i, l, r}, p, nl) : Bool}
654      %Equal.sym(Bool, ST.rep(~K, r, i, setc(K, nl, id, v)), ST.rep(~K, r, i, nl), rep_setc(~K, r, i, nl, id, v)) : {Bool.and(Nat.is_lt(0n, i), Bool.and(ST.is_node(K, ST.nd(K, nl, i), ST.rid(l), ST.rid(r), p), Bool.and(ST.rep(~K, l, i, nl), _))) == ST.rep(~K, ST.TN{i, l, r}, p, nl) : Bool}
655      {==}
656
657def ctx_setc(~K: Data, +c: List<&2, P.Fr>, +x: Nat, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Bool) -> {P.ctxok(~K, c, x, setc(K, nl, id, v)) == P.ctxok(~K, c, x, nl) : Bool}:
658  match c:
659    case Nil{}:
660      {==}
661    case Con{P.FR{+p, +lft, +s}, +u}:
662      %Equal.sym(Bool, ST.is_node(K, ST.nd(K, setc(K, nl, id, v), p), ST.pk(Nat, lft, x, ST.rid(s)), ST.pk(Nat, lft, ST.rid(s), x), P.top(u)), ST.is_node(K, ST.nd(K, nl, p), ST.pk(Nat, lft, x, ST.rid(s)), ST.pk(Nat, lft, ST.rid(s), x), P.top(u)), isn_setc(K, nl, id, v, p, ST.pk(Nat, lft, x, ST.rid(s)), ST.pk(Nat, lft, ST.rid(s), x), P.top(u))) : {Bool.and(Bool.and(Nat.is_lt(0n, p), Bool.and(_, ST.rep(~K, s, p, setc(K, nl, id, v)))), P.ctxok(~K, u, p, setc(K, nl, id, v))) == P.ctxok(~K, Con{P.FR{p, lft, s}, u}, x, nl) : Bool}
663      %Equal.sym(Bool, ST.rep(~K, s, p, setc(K, nl, id, v)), ST.rep(~K, s, p, nl), rep_setc(~K, s, p, nl, id, v)) : {Bool.and(Bool.and(Nat.is_lt(0n, p), Bool.and(ST.is_node(K, ST.nd(K, nl, p), ST.pk(Nat, lft, x, ST.rid(s)), ST.pk(Nat, lft, ST.rid(s), x), P.top(u)), _)), P.ctxok(~K, u, p, setc(K, nl, id, v))) == P.ctxok(~K, Con{P.FR{p, lft, s}, u}, x, nl) : Bool}
664      %Equal.sym(Bool, P.ctxok(~K, u, p, setc(K, nl, id, v)), P.ctxok(~K, u, p, nl), ctx_setc(~K, u, p, nl, id, v)) : {Bool.and(Bool.and(Nat.is_lt(0n, p), Bool.and(ST.is_node(K, ST.nd(K, nl, p), ST.pk(Nat, lft, x, ST.rid(s)), ST.pk(Nat, lft, ST.rid(s), x), P.top(u)), ST.rep(~K, s, p, nl))), _) == P.ctxok(~K, Con{P.FR{p, lft, s}, u}, x, nl) : Bool}
665      {==}
666
667# the recoloured node's colour
668def red_modc(-K: Data, +x: M.Node<K>, +v: Bool, +h: {ST.is_red(K, x) == ST.is_red(K, x) : Bool}) -> {ST.is_red(K, modc(K, x, False{})) == False{} : Bool}:
669  match x:
670    case M.Free{f}:
671      {==}
672    case M.N{c, a, b, q, k}:
673      {==}
674
675# ---- link setters keep every colour ----
676
677def red_modl(-K: Data, +x: M.Node<K>, +v: Nat) -> {ST.is_red(K, modl(K, x, v)) == ST.is_red(K, x) : Bool}:
678  match x:
679    case M.Free{f}:
680      {==}
681    case M.N{c, a, b, q, k}:
682      {==}
683
684def red_pkl(-K: Data, +e: Bool, +x: M.Node<K>, +v: Nat) -> {ST.is_red(K, ST.pk(M.Node<K>, e, modl(K, x, v), x)) == ST.is_red(K, x) : Bool}:
685  match e:
686    case True{}:
687      red_modl(K, x, v)
688    case False{}:
689      {==}
690
691def red_setl(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat) -> {ST.is_red(K, ST.nd(K, setl(K, nl, id, v), j)) == ST.is_red(K, ST.nd(K, nl, j)) : Bool}:
692  %Equal.sym(M.Node<K>, ST.nd(K, setl(K, nl, id, v), j), ST.pk(M.Node<K>, Nat.is_eq(id, j), modl(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)), ndl(K, nl, id, v, j)) : {ST.is_red(K, _) == ST.is_red(K, ST.nd(K, nl, j)) : Bool}
693  red_pkl(K, Nat.is_eq(id, j), ST.nd(K, nl, j), v)
694
695def red_modr(-K: Data, +x: M.Node<K>, +v: Nat) -> {ST.is_red(K, modr(K, x, v)) == ST.is_red(K, x) : Bool}:
696  match x:
697    case M.Free{f}:
698      {==}
699    case M.N{c, a, b, q, k}:
700      {==}
701
702def red_pkr(-K: Data, +e: Bool, +x: M.Node<K>, +v: Nat) -> {ST.is_red(K, ST.pk(M.Node<K>, e, modr(K, x, v), x)) == ST.is_red(K, x) : Bool}:
703  match e:
704    case True{}:
705      red_modr(K, x, v)
706    case False{}:
707      {==}
708
709def red_setr(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat) -> {ST.is_red(K, ST.nd(K, setr(K, nl, id, v), j)) == ST.is_red(K, ST.nd(K, nl, j)) : Bool}:
710  %Equal.sym(M.Node<K>, ST.nd(K, setr(K, nl, id, v), j), ST.pk(M.Node<K>, Nat.is_eq(id, j), modr(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)), ndr(K, nl, id, v, j)) : {ST.is_red(K, _) == ST.is_red(K, ST.nd(K, nl, j)) : Bool}
711  red_pkr(K, Nat.is_eq(id, j), ST.nd(K, nl, j), v)
712
713def red_modp(-K: Data, +x: M.Node<K>, +v: Nat) -> {ST.is_red(K, modp(K, x, v)) == ST.is_red(K, x) : Bool}:
714  match x:
715    case M.Free{f}:
716      {==}
717    case M.N{c, a, b, q, k}:
718      {==}
719
720def red_pkp(-K: Data, +e: Bool, +x: M.Node<K>, +v: Nat) -> {ST.is_red(K, ST.pk(M.Node<K>, e, modp(K, x, v), x)) == ST.is_red(K, x) : Bool}:
721  match e:
722    case True{}:
723      red_modp(K, x, v)
724    case False{}:
725      {==}
726
727def red_setp(-K: Data, +nl: List<&2, M.Node<K>>, +id: Nat, +v: Nat, +j: Nat) -> {ST.is_red(K, ST.nd(K, setp(K, nl, id, v), j)) == ST.is_red(K, ST.nd(K, nl, j)) : Bool}:
728  %Equal.sym(M.Node<K>, ST.nd(K, setp(K, nl, id, v), j), ST.pk(M.Node<K>, Nat.is_eq(id, j), modp(K, ST.nd(K, nl, j), v), ST.nd(K, nl, j)), ndp(K, nl, id, v, j)) : {ST.is_red(K, _) == ST.is_red(K, ST.nd(K, nl, j)) : Bool}
729  red_pkp(K, Nat.is_eq(id, j), ST.nd(K, nl, j), v)