@derivation of laviSISTa

The derivation of laviSISTa लविषीष्ट (benedictive /Atmanepada) is quite tricky.

As /liG is soft by liGAziSi, kartarizap won't work —

In a nutshell —

lU लू + soft /liG /ta
→ lU लू + **sISTa सीष्ट by several rules
→ lU लू + i इ + sISTa सीष्ट by ArdhadhAtuk...
→ lU लू + iSISTa इषीष्ट by /Satvam
→ lo लो + iSISTa इषीष्ट by gbS
→ lav लव् + iSISTa इषीष्ट by ecoyavAyAvaH
→ !**laviSISTa लविषीष्ट "may he cut"

In detail —

lU लू + soft /liG /ta
→ lU लू + /sIyuT + /ta by liGassIyuT
→ lU लू + /sIyuT + sta स्त by suTtithoH
→ lU लू + sIysta सीय्स्त
→ lU लू + sIsta सीस्त by lopovyorvali
→ lU लू + sISta सीष्त by /Satvam
→ lU लू + sISTa सीष्ट by STunASTuH

As sIyuT is an augment, this sISTa सीष्ट is still a single affix substituting /liG. As **sISTa सीष्ट is soft by liGAziSi, it gets /iT by ArdhadhAtuk... —

→ lU लू + /iT + sISTa सीष्ट
→ lU लू + iSISTa इषीष्ट by /Satvam
→ lo लो + iSISTa इषीष्ट by gbS
→ **laviSISTa लविषीष्ट "may he cut" by ecoyavAyAvaH.