def internal_lt_sub_zero
import bend-mathlib@0.8.1.0/nat.bend as Natimport Base
1797def internal_lt_sub_zero(a: Nat, p: Nat) -> {Nat.is_lt(a, Nat.sub(0n, 1n+p)) == Nat.is_lt(Nat.add(1n+p, a), 0n) : Bool}:
1798 match a:
1799 case 0n:
1800 {==}
1801 case 1n+x:
1802 {==}