def fits_of.step

bendtorch-core@0.1.0.0 · src/shape/coordinate_proofs.bend:115

import Base
import bendtorch-core@0.1.0.0/src/shape/core.bend as Shape

115def fits_of.step(-dh: Nat, -dt: List<&2, Nat>, -vh: Nat, -vt: List<&2, Nat>, verdict: Shape.BoolCase<Nat.is_lt(vh, dh)>, ok: {True{} == Bool.and(Nat.is_lt(vh, dh), Shape.fit(dt, vt)) : Bool}, rec: {True{} == Shape.fit(dt, vt) : Bool} -> Fits(dt, vt)) -> Fits(dh <> dt, vh <> vt):
116  match verdict:
117    case Shape.BFalse{equal}:
118      Empty.absurd(Fits(dh <> dt, vh <> vt), Shape.clash(Equal.trans(Bool, True{}, Bool.and(Nat.is_lt(vh, dh), Shape.fit(dt, vt)), False{}, ok, Equal.cong(Bool, Bool, head => Bool.and(head, Shape.fit(dt, vt)), Nat.is_lt(vh, dh), False{}, Equal.sym(Bool, False{}, Nat.is_lt(vh, dh), equal)))))
119    case Shape.BTrue{+equal}:
120      FStep{equal, rec(Equal.trans(Bool, True{}, Bool.and(Nat.is_lt(vh, dh), Shape.fit(dt, vt)), Shape.fit(dt, vt), ok, Equal.cong(Bool, Bool, head => Bool.and(head, Shape.fit(dt, vt)), Nat.is_lt(vh, dh), True{}, Equal.sym(Bool, True{}, Nat.is_lt(vh, dh), equal))))}