function pow( x, y ) {
	if ( x === -1.0 ) {
		// Julia (0.4.2) and Python (2.7.9) return `1.0` (WTF???). JavaScript (`Math.pow`), R, and libm return `NaN`. We choose `NaN`, as the value is indeterminate; i.e., we cannot determine whether `y` is odd, even, or somewhere in between.
		return (x-x)/(x-x); // signal NaN
	}
	if ( x === 1.0 ) {
		return 1.0;
	}
	// (|x| > 1 && y === NINF) || (|x| < 1 && y === PINF)
	if ( (abs(x) < 1.0) === (y === PINF) ) {
		return 0.0;
	}
	// (|x| > 1 && y === PINF) || (|x| < 1 && y === NINF)
	return PINF;
}
Evaluates the exponential function when \\( y = \pm \infty\\).

@private
@param {number} x - base
@param {number} y - exponent
@returns {number} function value

@example
var v = pow( -1.0, Infinity );
// returns NaN

@example
var v = pow( -1.0, -Infinity  );
// returns NaN

@example
var v = pow( 1.0, Infinity );
// returns 1.0

@example
var v = pow( 1.0, -Infinity  );
// returns 1.0

@example
var v = pow( 0.5, Infinity );
// returns 0.0

@example
var v = pow( 0.5, -Infinity  );
// returns Infinity

@example
var v = pow( 1.5, -Infinity  );
// returns 0.0

@example
var v = pow( 1.5, Infinity );
// returns Infinity