* interp/nruncomp.boot (NRTsetVector4Part1): Add environment parameter.
	Adjust caller.
	(NRTsetVector4a): Likewise.  Avoid special variable for environment.
	* boot/utility.boot: Add and export substSource, substTarget.
	* interp/define.boot: Use them.



git-svn-id: svn://svn.code.sf.net/p/open-axiom/code/trunk@2997 f499efd5-9937-0410-b36a-d3739c31ded8