public override string ToInputString() { return(string.Format("(not {0})", inner.ToInputString())); }
public override string ToInputString() { return(string.Format("(iff {0} {1})", left.ToInputString(), right.ToInputString())); }
public override string ToInputString() { return(string.Format("(if {0} {1})", antecedent.ToInputString(), consequent.ToInputString())); }