Given A, B, C any string or maths code, given + any operation of my choice, I would like to display a really simple calculation - here addition. On below the result I would like to obtain :
A +B __ C
I can't do it here, but please see the underline as right under B (not my above ugly displaying). A, B and C should be aligned. The operator is displayed on the left of B.
Actually, I am wondering if there is a package for that, to perform this simply ?