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Re: logical expressions

• To: mathgroup at yoda.ncsa.uiuc.edu
• Subject: Re: logical expressions
• From: Jim_Wendel at ub.cc.umich.edu
• Date: Tue, 13 Nov 90 09:25:34 EST

This is about Paul Abbott's note of 10/28, logical expressions.
The second example, supposedly of an invalid formula, is incorrect,
in the sense that the formula evaluates to q for every p, not to false;
this is readily checked by doing a truth-table by hand.
Furthermore, what is the role of the quantity e=Rep[1,gbool,2}?
It evaluates to 1, so why not just use 1, or nothing at all in multiplicative
environments, e.g. and[x_,y_]:=x y, rather than e x y?