Linkage adding mechanism 2

Combination of two pantograph mechanisms. Yellow and orange bars create a rhombus. Center distances from middle hole to end holes of yellow bar are equal. Pink, violet, grey and green bars create a rhombus. Center distances from middle hole to end holes of pink or green bar are equal. The mechanism ensures: OA OB = OC Move slider A to enter value X Move slider B to enter value Y Slider C shows S = X Y The video shows the operation 1 3 = 4 and the return to initial position.