src/Chippyash/Math/Type/Calculator/Native.php
public function naturalMul(NI $a, NI $b)
    {
        list($a, $b) = $this->checkIntTypes($a, $b);
        return new NaturalIntType($a() * $b());
    }
public function naturalMul(NI $a, NI $b)
    {
        list($a, $b) = $this->checkIntTypes($a, $b);
        return new NaturalIntType($a() * $b());
    }
public function naturalMul ( NI $ a , NI $ b ) { list ( $ a , $ b ) = $ this -> checkIntTypes ( $ a , $ b ) ; return new NaturalIntType ( $ a ( ) * $ b ( ) ) ; }
Natural number multiplication

@param NI $a first operand
@param NI $b second operand

@return NaturalIntType
Natural number multiplication