Continue parsing formulas

src/format.rs

@@ -389,12 +389,28 @@ impl<'formula> std::fmt::Debug for FormulaDisplay<'formula>
 					separator = " or "
 				}
 			},
-			crate::Formula::Implies(crate::Implies{antecedent, implication})
-				=> write!(format, "{:?} -> {:?}", display_formula(antecedent, precedence),
-					display_formula(implication, precedence))?,
-			crate::Formula::IfAndOnlyIf(crate::IfAndOnlyIf{left, right})
-				=> write!(format, "{:?} <-> {:?}", display_formula(left, precedence),
-					display_formula(right, precedence))?,
+			crate::Formula::Implies(crate::Implies{direction, antecedent, implication}) =>
+			{
+				let operator_symbol = match direction
+				{
+					crate::ImplicationDirection::LeftToRight => "->",
+					crate::ImplicationDirection::RightToLeft => "<-",
+				};
+
+				write!(format, "{:?} {} {:?}", display_formula(antecedent, precedence),
+					operator_symbol, display_formula(implication, precedence))?;
+			},
+			crate::Formula::IfAndOnlyIf(arguments) =>
+			{
+				let mut separator = "";
+
+				for argument in arguments
+				{
+					write!(format, "{}{:?}", separator, display_formula(argument, precedence))?;
+
+					separator = " <-> ";
+				}
+			},
 			crate::Formula::Compare(
 				crate::Compare{operator: crate::ComparisonOperator::Less, left, right})
 				=> write!(format, "{:?} < {:?}", display_term(left, None),