Nat.sub_zero: def of bend-collections-laws-math@1.0.0.0 Import: import bend-collections-laws-math@1.0.0.0/proofs/lib/nat.bend as Nat Lines 283-288 of bend-collections-laws-math@1.0.0.0/proofs/lib/nat.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/proofs/lib/nat.bend&start_line=283&end_line=288 import Base def sub_zero(+n: Nat) -> {Nat.sub(n, 0n) == n : Nat}: match n: case 0n: {==} case 1n+p: {==} Uses (2): https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub