We prove the intermediate
claim Hxlt0':
x < 0.
We prove the intermediate
claim Hxlt0y:
x < mul_SNo 0 y.
rewrite the current goal using
(mul_SNo_zeroL y HyS) (from right to left) at position 1.
An exact proof term for the current goal is Hxlt0y.
We prove the intermediate
claim Hxle0:
x ≤ 0.
An
exact proof term for the current goal is
(SNoLtLe x 0 Hxlt0').
We prove the intermediate
claim Heq0:
x = 0.
We prove the intermediate
claim H00:
0 < 0.
rewrite the current goal using Heq0 (from right to left) at position 1.
An exact proof term for the current goal is Hxlt0'.