- language to define type equality rigorously - language for type guards - fixed language for break statements
- language to define type equality rigorously
- language for type guards
- fixed language for break statements

Also: Removed uses of "we" and replaced by impersonal language.
Minor cosmetic changes.

DELTA=237  (160 added, 34 deleted, 43 changed)
OCL=18620
CL=18800

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go