# Question: if b is a wf well founded formula that...

###### Question details

If B is a wf ( well founded formula) that does not contain the = symbol and B is provable in predicate calculus with equality K, show that B is provable in K without using (A6) or (A7)

(A6) (∀x1)x1=x1 (reflexivity of equality)

(A7) x=y→(B(x,x)→B(x,y)) (substitutivity of equality)

Where wf= "well-founded formula"