diff --git a/src/format/formulas.rs b/src/format/formulas.rs
index a662062..ce7b0f1 100644
--- a/src/format/formulas.rs
+++ b/src/format/formulas.rs
@@ -107,17 +107,7 @@ impl<'formula> FormulaDisplay<'formula>
 					},
 				_ => false,
 			},
-			Formula::IfAndOnlyIf(_) => match *parent_formula
-			{
-				Formula::Not(_)
-				| Formula::Exists(_)
-				| Formula::ForAll(_)
-				| Formula::And(_)
-				| Formula::Or(_)
-				| Formula::Implies(_)
-					=> true,
-				_ => false,
-			},
+			Formula::IfAndOnlyIf(_) => true,
 		}
 	}
 }
@@ -870,43 +860,41 @@ mod tests
 	}
 
 	#[test]
-	fn format_combination_not_and_lower()
+	fn format_combinations_not()
 	{
 		// Not + not
 		assert!(not(not(p())), "not not p");
 
-		// Not + quantified formulas
-		assert_all!(i, not(exists(xyz(), i(p()))), "not exists X, Y, Z p");
-		assert_all!(i, not(for_all(xyz(), i(p()))), "not forall X, Y, Z p");
+		// Quantified formulas + not
+		assert_all!(i, exists(xyz(), i(not(p()))), "exists X, Y, Z not p");
 		assert_all!(i, for_all(xyz(), i(not(p()))), "forall X, Y, Z not p");
 
-		// Not + and
-		assert_all!(i, and(vec![not(i(p()))]), "not p");
-		assert_all!(i, not(i(and(pqr()))), "not (p and q and r)");
+		// And + not
+		assert_all!(i, and(vec![i(not(p()))]), "not p");
 		assert_all!(i, and(vec![i(not(p())), i(not(q())), i(not(r()))]),
 			"not p and not q and not r");
 
-		// Not + or
+		// Or + not
 		assert_all!(i, or(vec![i(not(p()))]), "not p");
-		assert_all!(i, not(i(or(pqr()))), "not (p or q or r)");
 		assert_all!(i, or(vec![i(not(p())), i(not(q())), i(not(r()))]), "not p or not q or not r");
 
-		// Not + implies
-		assert_all!(i, not(i(implies_right(p(), q()))), "not (p -> q)");
-		assert_all!(i, not(i(implies_left(p(), q()))), "not (q <- p)");
+		// Implies + not
 		assert_all!(i, implies_right(i(not(p())), i(not(q()))), "not p -> not q");
 		assert_all!(i, implies_left(i(not(p())), i(not(q()))), "not q <- not p");
 
-		// Not + if and only if
+		// If and only if + not
 		assert_all!(i, if_and_only_if(vec![i(not(p()))]), "not p");
-		assert_all!(i, not(i(if_and_only_if(pqr()))), "not (p <-> q <-> r)");
 		assert_all!(i, if_and_only_if(vec![i(not(p())), i(not(q())), i(not(r()))]),
 			"not p <-> not q <-> not r");
 	}
 
 	#[test]
-	fn format_combination_quantified_formula_and_lower()
+	fn format_combinations_quantified_formula()
 	{
+		// Not + quantified formula
+		assert_all!(i, not(exists(xyz(), i(p()))), "not exists X, Y, Z p");
+		assert_all!(i, not(for_all(xyz(), i(p()))), "not forall X, Y, Z p");
+
 		// Quantified formula + quantified formula
 		assert_all!(i, exists(x1y1z1(), i(exists(x2y2z2(), p()))),
 			"exists X1, Y1, Z1 exists X2, Y2, Z2 p");
@@ -917,91 +905,87 @@ mod tests
 		assert_all!(i, for_all(x1y1z1(), i(for_all(x2y2z2(), p()))),
 			"forall X1, Y1, Z1 forall X2, Y2, Z2 p");
 
-		// Quantified formula + and
-		assert_all!(i, exists(xyz(), i(and(pqr()))), "exists X, Y, Z (p and q and r)");
+		// And + quantified formula
+		assert_all!(i, and(vec![i(exists(xyz(), p()))]), "exists X, Y, Z p");
+		assert_all!(i, and(vec![i(for_all(xyz(), p()))]), "forall X, Y, Z p");
 		assert_all!(i, and(vec![i(exists(x1y1z1(), p())), i(exists(x2y2z2(), q())),
 			i(exists(x3y3z3(), r()))]),
 			"exists X1, Y1, Z1 p and exists X2, Y2, Z2 q and exists X3, Y3, Z3 r");
-		assert_all!(i, for_all(xyz(), i(and(pqr()))), "forall X, Y, Z (p and q and r)");
 		assert_all!(i, and(vec![i(for_all(x1y1z1(), p())), i(for_all(x2y2z2(), q())),
 			i(for_all(x3y3z3(), r()))]),
 			"forall X1, Y1, Z1 p and forall X2, Y2, Z2 q and forall X3, Y3, Z3 r");
 
-		// Quantified formula + or
-		assert_all!(i, exists(xyz(), i(or(pqr()))), "exists X, Y, Z (p or q or r)");
+		// Or + quantified formula
+		assert_all!(i, or(vec![i(exists(xyz(), p()))]), "exists X, Y, Z p");
+		assert_all!(i, or(vec![i(for_all(xyz(), p()))]), "forall X, Y, Z p");
 		assert_all!(i, or(vec![i(exists(x1y1z1(), p())), i(exists(x2y2z2(), q())),
 			i(exists(x3y3z3(), r()))]),
 			"exists X1, Y1, Z1 p or exists X2, Y2, Z2 q or exists X3, Y3, Z3 r");
-		assert_all!(i, for_all(xyz(), i(or(pqr()))), "forall X, Y, Z (p or q or r)");
 		assert_all!(i, or(vec![i(for_all(x1y1z1(), p())), i(for_all(x2y2z2(), q())),
 			i(for_all(x3y3z3(), r()))]),
 			"forall X1, Y1, Z1 p or forall X2, Y2, Z2 q or forall X3, Y3, Z3 r");
 
-		// Quantified formula + implies
-		assert_all!(i, exists(xyz(), i(implies_right(p(), q()))), "exists X, Y, Z (p -> q)");
-		assert_all!(i, exists(xyz(), i(implies_left(p(), q()))), "exists X, Y, Z (q <- p)");
+		// Implies + quantified formula
 		assert_all!(i, implies_right(i(exists(x1y1z1(), p())), i(exists(x2y2z2(), q()))),
 			"exists X1, Y1, Z1 p -> exists X2, Y2, Z2 q");
 		assert_all!(i, implies_left(i(exists(x1y1z1(), p())), i(exists(x2y2z2(), q()))),
 			"exists X2, Y2, Z2 q <- exists X1, Y1, Z1 p");
-		assert_all!(i, for_all(xyz(), i(implies_right(p(), q()))), "forall X, Y, Z (p -> q)");
-		assert_all!(i, for_all(xyz(), i(implies_left(p(), q()))), "forall X, Y, Z (q <- p)");
 		assert_all!(i, implies_right(i(for_all(x1y1z1(), p())), i(for_all(x2y2z2(), q()))),
 			"forall X1, Y1, Z1 p -> forall X2, Y2, Z2 q");
 		assert_all!(i, implies_left(i(for_all(x1y1z1(), p())), i(for_all(x2y2z2(), q()))),
 			"forall X2, Y2, Z2 q <- forall X1, Y1, Z1 p");
 
-		// Quantified formula + if and only if
-		assert_all!(i, exists(xyz(), i(if_and_only_if(pqr()))), "exists X, Y, Z (p <-> q <-> r)");
+		// If and only if + quantified formula
+		assert_all!(i, if_and_only_if(vec![i(exists(x1y1z1(), p()))]), "exists X1, Y1, Z1 p");
+		assert_all!(i, if_and_only_if(vec![i(for_all(x1y1z1(), p()))]), "forall X1, Y1, Z1 p");
 		assert_all!(i, if_and_only_if(vec![i(exists(x1y1z1(), p())), i(exists(x2y2z2(), q())),
 			i(exists(x3y3z3(), r()))]),
 			"exists X1, Y1, Z1 p <-> exists X2, Y2, Z2 q <-> exists X3, Y3, Z3 r");
-		assert_all!(i, for_all(xyz(), i(if_and_only_if(pqr()))), "forall X, Y, Z (p <-> q <-> r)");
 		assert_all!(i, if_and_only_if(vec![i(for_all(x1y1z1(), p())), i(for_all(x2y2z2(), q())),
 			i(for_all(x3y3z3(), r()))]),
 			"forall X1, Y1, Z1 p <-> forall X2, Y2, Z2 q <-> forall X3, Y3, Z3 r");
 	}
 
 	#[test]
-	fn format_combination_and_and_lower()
+	fn format_combinations_and()
 	{
+		// Not + and
+		assert_all!(i, not(i(and(vec![p()]))), "not p");
+		assert_all!(i, not(i(and(pqr()))), "not (p and q and r)");
+
+		// Quantified formula + and
+		assert_all!(i, exists(xyz(), i(and(vec![p()]))), "exists X, Y, Z p");
+		assert_all!(i, for_all(xyz(), i(and(vec![p()]))), "forall X, Y, Z p");
+		assert_all!(i, exists(xyz(), i(and(pqr()))), "exists X, Y, Z (p and q and r)");
+		assert_all!(i, for_all(xyz(), i(and(pqr()))), "forall X, Y, Z (p and q and r)");
+
 		// And + and
+		assert_all!(i, and(vec![i(and(vec![p()]))]), "p");
+		assert_all!(i, and(vec![i(and(pqr()))]), "p and q and r");
 		assert_all!(i, and(vec![i(and(vec![p()])), i(and(vec![q()])), i(and(vec![r()]))]),
 			"p and q and r");
 		assert_all!(i, and(vec![i(and(p1q1r1())), i(and(p2q2r2())), i(and(p3q3r3()))]),
 			"p1 and q1 and r1 and p2 and q2 and r2 and p3 and q3 and r3");
 
-		// And + or
-		assert_all!(i, and(vec![i(or(vec![p()])), i(or(vec![q()])), i(or(vec![r()]))]),
-			"p and q and r");
-		assert_all!(i, and(vec![i(or(p1q1r1())), i(or(p2q2r2())), i(or(p3q3r3()))]),
-			"(p1 or q1 or r1) and (p2 or q2 or r2) and (p3 or q3 or r3)");
-
+		// Or + and
+		assert_all!(i, or(vec![i(and(vec![p()]))]), "p");
+		assert_all!(i, or(vec![i(and(pqr()))]), "p and q and r");
 		assert_all!(i, or(vec![i(and(vec![p()])), i(and(vec![q()])), i(and(vec![r()]))]),
 			"p or q or r");
 		assert_all!(i, or(vec![i(and(p1q1r1())), i(and(p2q2r2())), i(and(p3q3r3()))]),
 			"p1 and q1 and r1 or p2 and q2 and r2 or p3 and q3 and r3");
 
-		// And + implies
-		assert_all!(i, and(vec![i(implies_right(p1(), q1())), i(implies_right(p2(), q2())),
-			i(implies_right(p3(), q3()))]),
-			"(p1 -> q1) and (p2 -> q2) and (p3 -> q3)");
-		assert_all!(i, and(vec![i(implies_left(p1(), q1())), i(implies_left(p2(), q2())),
-			i(implies_left(p3(), q3()))]),
-			"(q1 <- p1) and (q2 <- p2) and (q3 <- p3)");
+		// Implies + and
+		assert_all!(i, implies_right(i(and(vec![p()])), i(and(vec![q()]))), "p -> q");
+		assert_all!(i, implies_left(i(and(vec![p()])), i(and(vec![q()]))), "q <- p");
 		assert_all!(i, implies_right(i(and(p1q1r1())), i(and(p2q2r2()))),
 			"p1 and q1 and r1 -> p2 and q2 and r2");
 		assert_all!(i, implies_left(i(and(p1q1r1())), i(and(p2q2r2()))),
 			"p2 and q2 and r2 <- p1 and q1 and r1");
 
-		// And + if and only if
-		assert_all!(i, and(vec![i(if_and_only_if(vec![p()])), i(if_and_only_if(vec![q()])),
-			i(if_and_only_if(vec![r()]))]),
-			"p and q and r");
-		assert_all!(i, and(vec![i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2())),
-			i(if_and_only_if(p3q3r3()))]),
-			"(p1 <-> q1 <-> r1) and (p2 <-> q2 <-> r2) and (p3 <-> q3 <-> r3)");
-
+		// If and only if + and
+		assert_all!(i, if_and_only_if(vec![i(and(vec![p()]))]), "p");
+		assert_all!(i, if_and_only_if(vec![i(and(pqr()))]), "p and q and r");
 		assert_all!(i, if_and_only_if(vec![i(and(vec![p()])), i(and(vec![q()])),
 			i(and(vec![r()]))]),
 			"p <-> q <-> r");
@@ -1010,37 +994,45 @@ mod tests
 	}
 
 	#[test]
-	fn format_combination_or_and_lower()
+	fn format_combinations_or()
 	{
+		// Not + or
+		assert_all!(i, not(i(or(vec![p()]))), "not p");
+		assert_all!(i, not(i(or(pqr()))), "not (p or q or r)");
+
+		// Quantified formula + or
+		assert_all!(i, exists(xyz(), i(or(vec![p()]))), "exists X, Y, Z p");
+		assert_all!(i, for_all(xyz(), i(or(vec![p()]))), "forall X, Y, Z p");
+		assert_all!(i, exists(xyz(), i(or(pqr()))), "exists X, Y, Z (p or q or r)");
+		assert_all!(i, for_all(xyz(), i(or(pqr()))), "forall X, Y, Z (p or q or r)");
+
+		// And + or
+		assert_all!(i, and(vec![i(or(vec![p()]))]), "p");
+		assert_all!(i, and(vec![i(or(pqr()))]), "p or q or r");
+		assert_all!(i, and(vec![i(or(vec![p()])), i(or(vec![q()])), i(or(vec![r()]))]),
+			"p and q and r");
+		assert_all!(i, and(vec![i(or(p1q1r1())), i(or(p2q2r2())), i(or(p3q3r3()))]),
+			"(p1 or q1 or r1) and (p2 or q2 or r2) and (p3 or q3 or r3)");
+
 		// Or + or
+		assert_all!(i, or(vec![i(or(vec![p()]))]), "p");
+		assert_all!(i, or(vec![i(or(pqr()))]), "p or q or r");
 		assert_all!(i, or(vec![i(or(vec![p()])), i(or(vec![q()])), i(or(vec![r()]))]),
 			"p or q or r");
 		assert_all!(i, or(vec![i(or(p1q1r1())), i(or(p2q2r2())), i(or(p3q3r3()))]),
 			"p1 or q1 or r1 or p2 or q2 or r2 or p3 or q3 or r3");
 
-		// Or + implies
-		assert_all!(i, or(vec![i(implies_right(p1(), q1())), i(implies_right(p2(), q2())),
-			i(implies_right(p3(), q3()))]),
-			"(p1 -> q1) or (p2 -> q2) or (p3 -> q3)");
-		assert_all!(i, or(vec![i(and(vec![implies_right(p1(), q1())])),
-			i(and(vec![implies_right(p2(), q2())])), i(and(vec![implies_right(p3(), q3())]))]),
-			"(p1 -> q1) or (p2 -> q2) or (p3 -> q3)");
-		assert_all!(i, or(vec![i(implies_left(p1(), q1())), i(implies_left(p2(), q2())),
-			i(implies_left(p3(), q3()))]),
-			"(q1 <- p1) or (q2 <- p2) or (q3 <- p3)");
+		// Implies + or
+		assert_all!(i, implies_right(i(or(vec![p()])), i(or(vec![q()]))), "p -> q");
+		assert_all!(i, implies_left(i(or(vec![p()])), i(or(vec![q()]))), "q <- p");
 		assert_all!(i, implies_right(i(or(p1q1r1())), i(or(p2q2r2()))),
 			"p1 or q1 or r1 -> p2 or q2 or r2");
 		assert_all!(i, implies_left(i(or(p1q1r1())), i(or(p2q2r2()))),
 			"p2 or q2 or r2 <- p1 or q1 or r1");
 
-		// Or + if and only if
-		assert_all!(i, or(vec![i(if_and_only_if(vec![p()])), i(if_and_only_if(vec![q()])),
-			i(if_and_only_if(vec![r()]))]),
-			"p or q or r");
-		assert_all!(i, or(vec![i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2())),
-			i(if_and_only_if(p3q3r3()))]),
-			"(p1 <-> q1 <-> r1) or (p2 <-> q2 <-> r2) or (p3 <-> q3 <-> r3)");
-
+		// If and only if + or
+		assert_all!(i, if_and_only_if(vec![i(or(vec![p()]))]), "p");
+		assert_all!(i, if_and_only_if(vec![i(or(pqr()))]), "p or q or r");
 		assert_all!(i, if_and_only_if(vec![i(or(vec![p()])), i(or(vec![q()])), i(or(vec![r()]))]),
 			"p <-> q <-> r");
 		assert_all!(i, if_and_only_if(vec![i(or(p1q1r1())), i(or(p2q2r2())), i(or(p3q3r3()))]),
@@ -1048,8 +1040,38 @@ mod tests
 	}
 
 	#[test]
-	fn format_combination_implies_and_lower()
+	fn format_combinations_implies()
 	{
+		// Not + implies
+		assert_all!(i, not(i(implies_right(p(), q()))), "not (p -> q)");
+		assert_all!(i, not(i(implies_left(p(), q()))), "not (q <- p)");
+
+		// Quantified formula + implies
+		assert_all!(i, exists(xyz(), i(implies_right(p(), q()))), "exists X, Y, Z (p -> q)");
+		assert_all!(i, exists(xyz(), i(implies_left(p(), q()))), "exists X, Y, Z (q <- p)");
+		assert_all!(i, for_all(xyz(), i(implies_right(p(), q()))), "forall X, Y, Z (p -> q)");
+		assert_all!(i, for_all(xyz(), i(implies_left(p(), q()))), "forall X, Y, Z (q <- p)");
+
+		// And + implies
+		assert_all!(i, and(vec![i(implies_right(p(), q()))]), "p -> q");
+		assert_all!(i, and(vec![i(implies_left(p(), q()))]), "q <- p");
+		assert_all!(i, and(vec![i(implies_right(p1(), q1())), i(implies_right(p2(), q2())),
+			i(implies_right(p3(), q3()))]),
+			"(p1 -> q1) and (p2 -> q2) and (p3 -> q3)");
+		assert_all!(i, and(vec![i(implies_left(p1(), q1())), i(implies_left(p2(), q2())),
+			i(implies_left(p3(), q3()))]),
+			"(q1 <- p1) and (q2 <- p2) and (q3 <- p3)");
+
+		// Or + implies
+		assert_all!(i, or(vec![i(implies_right(p(), q()))]), "p -> q");
+		assert_all!(i, or(vec![i(implies_left(p(), q()))]), "q <- p");
+		assert_all!(i, or(vec![i(implies_right(p1(), q1())), i(implies_right(p2(), q2())),
+			i(implies_right(p3(), q3()))]),
+			"(p1 -> q1) or (p2 -> q2) or (p3 -> q3)");
+		assert_all!(i, or(vec![i(implies_left(p1(), q1())), i(implies_left(p2(), q2())),
+			i(implies_left(p3(), q3()))]),
+			"(q1 <- p1) or (q2 <- p2) or (q3 <- p3)");
+
 		// Implies + implies
 		assert_all!(i, implies_right(i(implies_right(p1(), q1())), i(implies_right(p2(), q2()))),
 			"(p1 -> q1) -> p2 -> q2");
@@ -1060,11 +1082,9 @@ mod tests
 		assert_all!(i, implies_left(i(implies_left(p1(), q1())), i(implies_left(p2(), q2()))),
 			"q2 <- p2 <- (q1 <- p1)");
 
-		// Implies + if and only if
-		assert_all!(i, implies_right(i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2()))),
-			"(p1 <-> q1 <-> r1) -> (p2 <-> q2 <-> r2)");
-		assert_all!(i, implies_left(i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2()))),
-			"(p2 <-> q2 <-> r2) <- (p1 <-> q1 <-> r1)");
+		// If and only if + implies
+		assert_all!(i, if_and_only_if(vec![i(implies_right(p(), q()))]), "p -> q");
+		assert_all!(i, if_and_only_if(vec![i(implies_left(p(), q()))]), "q <- p");
 		assert_all!(i, if_and_only_if(vec![i(implies_right(p1(), q1())),
 			i(implies_right(p2(), q2())), i(implies_right(p3(), q3()))]),
 			"p1 -> q1 <-> p2 -> q2 <-> p3 -> q3");
@@ -1072,4 +1092,58 @@ mod tests
 			i(implies_left(p3(), q3()))]),
 			"q1 <- p1 <-> q2 <- p2 <-> q3 <- p3");
 	}
+
+	#[test]
+	fn format_combinations_if_and_only_if()
+	{
+		// Not + if and only if
+		assert_all!(i, not(i(if_and_only_if(vec![p()]))), "not p");
+		assert_all!(i, not(i(if_and_only_if(pqr()))), "not (p <-> q <-> r)");
+
+		// Quantified formula + if and only if
+		assert_all!(i, exists(xyz(), i(if_and_only_if(vec![p()]))), "exists X, Y, Z p");
+		assert_all!(i, for_all(xyz(), i(if_and_only_if(vec![p()]))), "forall X, Y, Z p");
+		assert_all!(i, exists(xyz(), i(if_and_only_if(pqr()))), "exists X, Y, Z (p <-> q <-> r)");
+		assert_all!(i, for_all(xyz(), i(if_and_only_if(pqr()))), "forall X, Y, Z (p <-> q <-> r)");
+
+		// And + if and only if
+		assert_all!(i, and(vec![i(if_and_only_if(vec![p()]))]), "p");
+		assert_all!(i, and(vec![i(if_and_only_if(pqr()))]), "p <-> q <-> r");
+		assert_all!(i, and(vec![i(if_and_only_if(vec![p()])), i(if_and_only_if(vec![q()])),
+			i(if_and_only_if(vec![r()]))]),
+			"p and q and r");
+		assert_all!(i, and(vec![i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2())),
+			i(if_and_only_if(p3q3r3()))]),
+			"(p1 <-> q1 <-> r1) and (p2 <-> q2 <-> r2) and (p3 <-> q3 <-> r3)");
+
+		// Or + if and only if
+		assert_all!(i, or(vec![i(if_and_only_if(vec![p()]))]), "p");
+		assert_all!(i, or(vec![i(if_and_only_if(pqr()))]), "p <-> q <-> r");
+		assert_all!(i, or(vec![i(if_and_only_if(vec![p()])), i(if_and_only_if(vec![q()])),
+			i(if_and_only_if(vec![r()]))]),
+			"p or q or r");
+		assert_all!(i, or(vec![i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2())),
+			i(if_and_only_if(p3q3r3()))]),
+			"(p1 <-> q1 <-> r1) or (p2 <-> q2 <-> r2) or (p3 <-> q3 <-> r3)");
+
+		// Implies + if and only if
+		assert_all!(i, implies_right(i(if_and_only_if(vec![p()])), i(if_and_only_if(vec![q()]))),
+			"p -> q");
+		assert_all!(i, implies_left(i(if_and_only_if(vec![p()])), i(if_and_only_if(vec![q()]))),
+			"q <- p");
+		assert_all!(i, implies_right(i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2()))),
+			"(p1 <-> q1 <-> r1) -> (p2 <-> q2 <-> r2)");
+		assert_all!(i, implies_left(i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2()))),
+			"(p2 <-> q2 <-> r2) <- (p1 <-> q1 <-> r1)");
+
+		// If and only if + if and only if
+		assert_all!(i, if_and_only_if(vec![i(if_and_only_if(vec![p()]))]), "p");
+		assert_all!(i, if_and_only_if(vec![i(if_and_only_if(pqr()))]), "p <-> q <-> r");
+		assert_all!(i, if_and_only_if(vec![i(if_and_only_if(vec![p()])),
+			i(if_and_only_if(vec![q()])), i(if_and_only_if(vec![r()]))]),
+			"p <-> q <-> r");
+		assert_all!(i, if_and_only_if(vec![i(if_and_only_if(p1q1r1())), i(if_and_only_if(p2q2r2())),
+			i(if_and_only_if(p3q3r3()))]),
+			"(p1 <-> q1 <-> r1) <-> (p2 <-> q2 <-> r2) <-> (p3 <-> q3 <-> r3)");
+	}
 }