tuned module structure

tuned data structures

tuned target inheritance bookkeeping: ancestry is always fully maintained at current entry using canonical merge; n. b. merging of bidirectional dependencies results in effective join of involved nodes: no termination problem since ancestry is always kept explicitly normalized

tuned

tuned names

eta-expand all search patterns using schematic place holders

revert "better" handling of abbreviation from c61fe520602b

tuned variable names

turn application-specific Pattern.matches_subterm into an application-private function

cleaned up mess