napply I.
nqed.
-nlemma bsymmetric_eqnat : boolSymmetric nat eq_nat.
+nlemma symmetric_eqnat : symmetricT nat bool eq_nat.
nnormalize;
#n1;
nelim n1;
##| ##2: #n4; napply (H n4)
##]
##]
-nqed.
+nqed.
nlemma eq_to_eqnat : ∀n1,n2:nat.n1 = n2 → eq_nat n1 n2 = true.
#n1;
nelim n2;
nnormalize;
##[ ##1: #H; napply (refl_eq ??)
- ##| ##2: #n3; #H; #H1; nelim (bool_destruct_false_true H1)
+ ##| ##2: #n3; #H; #H1; napply (bool_destruct ?? (O = S n3) H1)
##]
##| ##2: #n2; #H; #n3; #H1;
ncases n3 in H1:(%) ⊢ %;
nnormalize;
- ##[ ##1: #H1; nelim (bool_destruct_false_true H1)
+ ##[ ##1: #H1; napply (bool_destruct ?? (S n2 = O) H1)
##| ##2: #n4; #H1;
nrewrite > (H n4 H1);
napply (refl_eq ??)