lemma1 : {c10 :!$\mathbb{N}$!} !$\rightarrow$! Axiom (stmt1Cond {c10}) (!$\lambda$! env !$\rightarrow$! record { varn = varn env ; vari = 0 }) (stmt2Cond {c\
10})
lemma1 {c10} env = impl!$\Rightarrow$! ( !$\lambda$! cond !$\rightarrow$! let open !$\equiv$!-Reasoning  in
begin
(Equal (varn env) c10 ) !$\wedge$! true
!$\equiv$!!$\langle$! !$\wedge$!true !$\rangle$!
Equal (varn env) c10
!$\equiv$!!$\langle$! cond !$\rangle$!
true
!$\blacksquare$! )