eqcomi

Theorem.

Arguments:

x (st), y (st),

Assertions:

((xeqy)to(yeqx))

Proof:

Hyp Ref Line Expr
eqid1(xeqx)
ax82((xeqy)to((xeqx)to(yeqx)))
1, 2mpi3((xeqy)to(yeqx))