I see her hunker down with her ears flattened to her back as she peers upward at the window ledge, eyeing the distance from her to to her destination. She only has her memory to let her know the state of the landing point which is just outside of her visual reference point.
she traces the rout with her eyes and positions her hind legs to set up a potential flight path. as her butt wiggles she shifts her weight to balance the load all the while her brain is calculateing the force needed to propel her mass at the needed velocity to achieve her desire to get from here to there.
The final solution is realized and the brain triggers a shower of electrical charges that control all of the muscles needed to generate and implement such exacting physical force.
all the while watching her termination looking for change, ready to reposition her body in mid flight if the need should arise.
A graceful descent from her most energetic position proves to me in my opinion that my cat is really really good at math.