How do I specify a lateral limit?

>>>>> "CY" == C Y <smustudent1@yahoo.com> writes:

    CY> 3.  Have the limit command treat the strings PLUS and MINUS specially,
    CY> regardless of their contents, and otherwise allow PLUS and MINUS to be
    CY> variables.  Only drawbacks here are that PLUS and MINUS variables
    CY> couldn't be fed to Limit command, and need to train the limit command
    CY> to handle this case.

I don't think this will work.  By the time limit gets run, it only
sees value of the fourth arg:

(C1) plus:42;

(D1) 				      42
(C2) foo:'plus;

(D2) 				     PLUS
(C3) limit(tan(x),x,%pi/2,foo);

Ray