src/eMacros/Runtime/Arithmetic/Subtraction.php
public function execute(array $arguments) {
    	if (empty($arguments)) throw new \InvalidArgumentException("Subtraction: At least 1 argument is required");
    	//emulate CLISP: (- 3) = -3
    	if (!isset($arguments[1])) return -$arguments[0];
    	//obtain first argument
        $result = array_shift($arguments);
        foreach ($arguments as $value)
        	$result -= $value;
        return $result;
    }
public function execute(array $arguments) {
    	if (empty($arguments)) throw new \InvalidArgumentException("Subtraction: At least 1 argument is required");
    	//emulate CLISP: (- 3) = -3
    	if (!isset($arguments[1])) return -$arguments[0];
    	//obtain first argument
        $result = array_shift($arguments);
        foreach ($arguments as $value)
        	$result -= $value;
        return $result;
    }
Obtains the result of subtracting the first element on a list by the rest of the elements.
Usage: (- 120 30 50)
Returns: number
(non-PHPdoc)
@see \eMacros\Runtime\GenericFunction::execute()