code: @Pure
  	public DoubleProperty x1Property() {
  		if (this.p1.x == null) {
  			this.p1.x = new SimpleDoubleProperty(this, MathFXAttributeNames.X1);
  		}
  		return this.p1.x;
  	}
docs: Replies the property that is the x coordinate of the first segment point.
  
  @return the x1 property.