function isPositiveZerof( x ) {
	return (x === 0.0 && 1.0/x === PINF);
}
Tests if a single-precision floating-point numeric value is positive zero.

@param {number} x - value to test
@returns {boolean} boolean indicating whether the value is positive zero

@example
var bool = isPositiveZerof( 0.0 );
// returns true

@example
var bool = isPositiveZerof( -0.0 );
// returns false