diff --git a/tests/muqsit/arithmexp/OptimizerTest.php b/tests/muqsit/arithmexp/OptimizerTest.php
index ac25fe1..9b693b8 100644
--- a/tests/muqsit/arithmexp/OptimizerTest.php
+++ b/tests/muqsit/arithmexp/OptimizerTest.php
@@ -61,7 +61,25 @@ public function testConstantPropagationOptimization() : void{
 		self::assertExpressionsEqual($expected, $actual);
 	}
 
-	public function testDivisionConstantFoldingForEqualOperandsReturningNan() : void{
+	public function testDivisionConstantFoldingForRightOperandNan() : void{
+		$expression = $this->parser->parse("min(1, 2) / nan");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+	}
+
+	public function testSubtractionConstantFoldingBetweenInf() : void{
+		$expression = $this->parser->parse("inf - inf");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+	}
+
+	public function testSubtractionConstantFoldingBetweenNan() : void{
+		$expression = $this->parser->parse("nan - nan");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+	}
+
+	public function testDivisionConstantFoldingForFunctionCallOperandsReturningNan() : void{
 		$expression = $this->parser->parse("sqrt(-1) / sqrt(-1)");
 		self::assertInstanceOf(ConstantExpression::class, $expression);
 		self::assertNan($expression->evaluate());
@@ -204,6 +222,16 @@ public function testDivisionOperatorStrengthReductionForEqualOperandsWithGroupin
 		self::assertEquals(1, $expression->evaluate());
 	}
 
+	public function testMultiplicationOperatorStrengthReductionForNanOperands() : void{
+		$expression = $this->parser->parse("nan * x");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+
+		$expression = $this->parser->parse("x * nan");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+	}
+
 	public function testDivisionOperatorStrengthReductionForCommutativelyEqualOperands() : void{
 		$expression = $this->parser->parse("(x + y + z) / (y + x + z)");
 		self::assertInstanceOf(ConstantExpression::class, $expression);
@@ -222,6 +250,12 @@ public function testDivisionOperatorStrengthReductionForLeftOperandZeroWithGroup
 		self::assertEquals(0, $expression->evaluate());
 	}
 
+	public function testDivisionOperatorStrengthReductionForRightOperandNan() : void{
+		$expression = $this->parser->parse("mt_rand(1, 2) / nan");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+	}
+
 	public function testDivisionOperatorStrengthReductionForRightOperandOne() : void{
 		$actual = $this->parser->parse("x / 1 + y / 1");
 		$expected = $this->unoptimized_parser->parse("x + y");
@@ -288,6 +322,16 @@ public function testAdditionOperatorStrengthReductionForOperandZeroWithGrouping(
 		self::assertExpressionsEqual($expected, $actual);
 	}
 
+	public function testAdditionOperatorStrengthReductionForNanOperands() : void{
+		$expression = $this->parser->parse("nan + x");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+
+		$expression = $this->parser->parse("x + nan");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+	}
+
 	public function testAdditionOperatorStrengthReductionForNegativeLeftOperand() : void{
 		$actual = $this->parser->parse("-x + y");
 		$expected = $this->unoptimized_parser->parse("y - x");
@@ -354,6 +398,16 @@ public function testSubtractionOperatorStrengthReductionForCommutativeFunctions(
 		self::assertEquals(0, $expression->evaluate());
 	}
 
+	public function testSubtractionOperatorStrengthReductionForNanOperands() : void{
+		$expression = $this->parser->parse("nan - x");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+
+		$expression = $this->parser->parse("x - nan");
+		self::assertInstanceOf(ConstantExpression::class, $expression);
+		self::assertNan($expression->evaluate());
+	}
+
 	public function testSubtractionOperatorStrengthReductionForNegativeLeftOperand() : void{
 		$actual = $this->parser->parse("-x - y");