equiv_simple - try proving simple $equiv instances

yosys> help equiv_simple
equiv_simple [options] [selection]
This command tries to prove $equiv cells using a simple direct SAT approach.
-v
verbose output
-undef
enable modelling of undef states
-short
create shorter input cones that stop at shared nodes. This yields
simpler SAT problems but sometimes fails to prove equivalence.
-nogroup
disabling grouping of $equiv cells by output wire
-seq <N>
the max. number of time steps to be considered (default = 1)