(a * (1 - t)) + (b * t) would be my favorite way to express this in a programming context, I don't really see the point of your proposition over prefix or stack

(a * (1 - t)) + (b * t) would be my favorite way to express this in a programming context, I don't really see the point of your proposition over prefix or stack: (+ (* a (- 1 t)) (* b t)) 1 t - a * b t * +