Arith.le_add_cancel: def of bend-collections-laws-math@1.0.0.0 Import: import bend-collections-laws-math@1.0.0.0/proofs/math/natural/arith.bend as Arith Lines 62-68 of bend-collections-laws-math@1.0.0.0/proofs/math/natural/arith.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/proofs/math/natural/arith.bend&start_line=62&end_line=68 import Base # d + x <= d + y is x <= y def le_add_cancel(+d: Nat, +x: Nat, +y: Nat) -> {Nat.is_le(Nat.add(d, x), Nat.add(d, y)) == Nat.is_le(x, y) : Bool}: match d: case 0n: {==} case 1n+ +dp: le_add_cancel(dp, x, y) Uses (4): https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_le