public override WFF Rename(Term s, Term d) { return(new Negation(inner.Rename(s, d))); }
public override WFF Rename(Term s, Term d) { return(new Biconditional( left.Rename(s, d), right.Rename(s, d))); }
public override WFF Rename(Term s, Term d) { return(new Conditional( antecedent.Rename(s, d), consequent.Rename(s, d))); }