rewrite the current goal using Heq (from left to right).
Use reflexivity.
An exact proof term for the current goal is Htmp.
We prove the intermediate
claim H11:
Rlt 1 1.
rewrite the current goal using Heq1 (from left to right) at position 1.
An
exact proof term for the current goal is
((not_Rlt_sym 1 1 H11) H11).
∎