In sh, is '[' a portable synonym for 'test'?

[J Q Johnson]

Although I personally prefer to write using [] rather than test, it has
the disadvantage of obscuring the generality of sh.  After all, the
conditional can be an arbitrary list, so
	if [ x = y ]; true; then echo yes; fi
prints "yes".  More generally, thinking of  [] as part of a special-purpose
conditional construct obscures the need for the following ";".  I have
several times made the syntax error:
	if [ -r whatever ] then
If I'd been using test, I wouldn't have forgotten the ";", since the
conditional would obviously have needed termination.