Fixed problem where there was only one alternative and the predicate could fail.
Fixed problem where there was only one alternative and the predicate could fail.

Also eliminated a bunch of predicate checks by taking advantage of situations where we know that fillers are separators (e.g. after commas).

git-svn-id: https://svn.sable.mcgill.ca/mclab/Project@495 89b902b4-d83f-0410-b942-89f7a419ffdb

Migrated from Sable/mclab@f9d3a6d2a43775939b6b30fe15c1f29155f63bf3

Sable/mclab-core,Sable/mclab-core,Sable/mclab-core,Sable/mclab-core,Sable/mclab-core,Sable/mclab-core,Sable/mclab-core,Sable/mclab-core