ProofBase.range_get.cases: def of minebender-game@1.0.0.0
Import: import minebender-game@1.0.0.0/proof_base.bend as ProofBase
Lines 356-373 of minebender-game@1.0.0.0/proof_base.bend: https://jend.leeeet.dev/read.txt?path=minebender-game@1.0.0.0/proof_base.bend&start_line=356&end_line=373

import Base

def range_get.cases(+p: Nat, +i: Nat,
  r: Or({Nat.is_lt(i, p) == True{} : Bool}, {i == p : Nat}),
  ih: {Nat.is_lt(i, p) == True{} : Bool} -> {List.get(&2, Nat, List.range(p), i) == Some{i} : Maybe<&2, Nat>}) ->
  {List.get(&2, Nat, List.append(&2, Nat, List.range(p), [p]), i) == Some{i} : Maybe<&2, Nat>}:
  match r:
    case Inl{+lt}:
      +lt2 = {%Equal.sym(Nat, List.length(&2, Nat, List.range(p)), p, range_length(p)) :
        {Nat.is_lt(i, _) == True{} : Bool}; lt : {Nat.is_lt(i, List.length(&2, Nat, List.range(p))) == True{} : Bool}}
      %Equal.sym(Maybe<&2, Nat>, List.get(&2, Nat, List.append(&2, Nat, List.range(p), [p]), i),
        List.get(&2, Nat, List.range(p), i), get_append_l(Nat, List.range(p), [p], i, lt2)) :
        {_ == Some{i} : Maybe<&2, Nat>}
      ih(lt)
    case Inr{eq}:
      %Equal.sym(Nat, i, p, eq) :
        {List.get(&2, Nat, List.append(&2, Nat, List.range(p), [p]), _) == Some{_} : Maybe<&2, Nat>}
      %range_length(p) :
        {List.get(&2, Nat, List.append(&2, Nat, List.range(p), [p]), _) == Some{p} : Maybe<&2, Nat>}
      get_append_len(Nat, List.range(p), p, Nil{})

Uses (15):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Either
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.append
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.get
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.length
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.range
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Or
  https://jend.leeeet.dev/definition.txt?path=minebender-game@1.0.0.0/proof_base.bend&name=get_append_l
  https://jend.leeeet.dev/definition.txt?path=minebender-game@1.0.0.0/proof_base.bend&name=get_append_len
  https://jend.leeeet.dev/definition.txt?path=minebender-game@1.0.0.0/proof_base.bend&name=range_length