def scale_within

bendtorch-core@0.1.0.0 · src/shape/construct_proofs.bend:20

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

20def scale_within(+head: Nat, -tail: List<&2, Nat>, +size: Nat, -exact: {size == Shape.numel(tail) : Nat}, +small: Shape.BoolCase<Bool.or(Nat.is_eq(size, 0n), Nat.is_le(head, 1048576n))>, fits_small: {True{} == Bool.or(Nat.is_eq(size, 0n), Nat.is_le(head, 1048576n)) : Bool}, fits_product: {True{} == Nat.is_le(Nat.mul(head, size), 1048576n) : Bool}) -> {True{} == within(head <> tail, Shape.capacity.scale(head, tail, size, exact, small)) : Bool}:
21  match small:
22    case Shape.BFalse{equal}:
23      Empty.absurd({True{} == False{} : Bool}, Nats.contradiction(Bool.or(Nat.is_eq(size, 0n), Nat.is_le(head, 1048576n)), fits_small, equal))
24    case Shape.BTrue{equal}:
25      bound_within(head <> tail, Nat.mul(head, size), Equal.cong(Nat, Nat, value => Nat.mul(head, value), size, Shape.numel(tail), exact), Shape.bool_case(Nat.is_le(Nat.mul(head, size), 1048576n)), fits_product)