<A NAME=GCD_switch>
<TITLE>GCD_switch</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>
<B>GCD</B> _ _ _ _ _ _ _ _ _ _ _ _ <B>switch</B><P>
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When <em>gcd</em> is on, common factors in numerators and denominators of
expressions are canceled. Default is <em>off</em>.
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examples: </H3>
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(2*(f*h)**2 - f**2*g*h - (f*g)**2 - f*h**3 + f*h*g**2
- h**4 + g*h**3)/(f**2*h - f**2*g - f*h**2 + 2*f*g*h
- f*g**2 - g*h**2 + g**2*h);
2 2 2 2 2 2 3 3 4
F *G + F *G*H - 2*F *H - F*G *H + F*H - G*H + H
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2 2 2 2 2 2
F *G - F *H + F*G - 2*F*G*H + F*H - G *H + G*H
on gcd;
ws;
2
F*G + 2*F*H + H
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F + G
e2 := a*c + a*d + b*c + b*d;
E2 := A*C + A*D + B*C + B*D
off exp;
e2;
(A + B)*(C + D)
</TT></PRE><P>Even with <em>gcd</em> off, a check is automatically made for comm
on variable
and numerical products in the numerators and denominators of expression,
and the appropriate cancellations made. Thus the example demonstrating the
use of <em>gcd</em> is somewhat complicated. Note when
<A HREF=r37_0256.html>exp</A> is off,
<em>gcd</em> has the side effect of factoring the expression.
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