Added function.e, global import and improved inheritance of PREDICATE

	new file:   library/kernel/function.e
	modified:   library/kernel/kernel.eml
	modified:   library/kernel/predicate.e
	modified:   ocaml/lexer.mll
	modified:   ocaml/parser.mly
	modified:   ocaml/support.ml
	modified:   ocaml/test.e
Added abstract sequence, axioms for the 'in' operator and introduction and elimination
rules for the exist operator 'some'

	new file:   library/kernel/abstract_sequence.e
	modified:   library/kernel/any.e
	modified:   library/kernel/boolean.e
	modified:   library/kernel/kernel.eml
	modified:   library/kernel/predicate.e
Factored out a library with a generic sequence and a generic symbol table
and added a symbol table of paths

	modified:   ocaml/parser.mly
	modified:   ocaml/support.ml
	modified:   ocaml/validate.ml