function incrmin() {
	var min;
	return accumulator;

	/**
	* If provided a value, the accumulator function returns an updated minimum value. If not provided a value, the accumulator function returns the current min.
	*
	* @private
	* @param {number} [x] - new value
	* @returns {(number|null)} min value or null
	*/
	function accumulator( x ) {
		if ( arguments.length === 0 ) {
			return ( min === void 0 ) ? null : min;
		}
		if (
			min === void 0 ||
			x < min ||
			isnan( x ) ||
			( x === min && isNegativeZero( x ) )
		) {
			min = x;
		}
		return min;
	}
}
Returns an accumulator function which incrementally computes a minimum value.

@returns {Function} accumulator function

@example
var accumulator = incrmin();

var min = accumulator();
// returns null

min = accumulator( 3.14 );
// returns 3.14

min = accumulator( -5.0 );
// returns -5.0

min = accumulator( 10.1 );
// returns -5.0

min = accumulator();
// returns -5.0