; you can use it in two ways:
; 1. as illustrated by the default text above, if
; you provide an LLVM IR function called src
; and one called tgt, alive-tv will try to prove
; that tgt refines src
; 2. otherwise, alive-tv will run an optimization
; pipeline similar to -O2 on your code, and then
; try to show that the optimized function(s)
; refine the original one(s)
;