mo-sb2con

Theorem.

Arguments:

a (st), b (st), x (sv), phi (pr),

Distinct variable conditions:

(x, a),

Assertions:

(([a/x]phiwedge[b/x]phi)to(lnot(aeqb)tolnot_em1xphi))

Proof:

Hyp Ref Line Expr
mo-sb21(_em1xphito(([a/x]phiwedge[b/x]phi)to(aeqb)))
1com12i2(([a/x]phiwedge[b/x]phi)to(_em1xphito(aeqb)))
2con3(([a/x]phiwedge[b/x]phi)to(lnot(aeqb)tolnot_em1xphi))