the first form curve integrals
adult of the first form
complex flat curve form error
Free-Form Curve and Surface
free-form curve surface
spatial free form curve
curve-curve intersection
transition curve；easement curve；spiral transition curve
alternate width-first and depth-first
FCFS First Come First Served
FEFO First – End First – Out
FEFO First C End First C Out
FIFO (first in and first out) memory
FIFO (first in first out)