@indigoparadox okay, remember I'm working with drafts of books written between Sandewall's retirement in 2010 and last visible activity in 2014. In AICA-SYSTEMS-1 at the start there's:
"3.2.4 The Prolog Language
An account of Prolog as a representation language is to be added here. Notice the relation to ICL in Section 6.4.
3.2.5 The Common Expression Language
Discuss how it relates to the previous ones. Many points in common with KIF [Knowledge Interchange Format -st], but more legible.." so