renamed runiq_replace → runiq_replace_2nd, runiq_replace' → runiq_replace_2nd'
renamed runiq_replace → runiq_replace_snd, runiq_replace' → runiq_replace_snd'
lemma runiq_replace_fst
renamed runiq_conv_replace → runiq_conv_replace_fst, runiq_conv_replace' → runiq_conv_replace_fst'
proved "runiq x'" inside wd_outcome