[Maxima-bugs] [maxima:bugs] #3285 radcan: failure to simplify to zero depending on slight change and/or ?expsumsplit

[David S. <tom...@us...>]

- Description has changed:

Diff:

~~~~

--- old
+++ new
@@ -1,4 +1,4 @@
-`radcan` fails to simplify an expression to zero that contains no variables, only logarithms of natural numbers. When we slightly rewrite the expression to an equivalent one, `radcan` succeeds. Applying `logcontract` also helps, as does setting the internal flag `?expsumsplit` to `false`:
+`radcan` fails to simplify an expression to zero that contains no variables, only exponentials and logarithms of natural numbers. When we slightly rewrite the expression to an equivalent one, `radcan` succeeds. Applying `logcontract` also helps, as does setting the internal flag `?expsumsplit` to `false`:
 ~~~
 (%i1)	X : 2^(log(3)/(log(2)-log(3)))-3^(log(3)/(log(2)-log(3))+1)$
 (%i2)	radcan(X);

~~~~




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** [bugs:#3285] radcan: failure to simplify to zero depending on slight change and/or ?expsumsplit**

**Status:** open
**Group:** None
**Labels:** radcan 
**Created:** Fri Feb 03, 2017 08:04 AM UTC by David Scherfgen
**Last Updated:** Fri Feb 03, 2017 08:04 AM UTC
**Owner:** nobody


`radcan` fails to simplify an expression to zero that contains no variables, only exponentials and logarithms of natural numbers. When we slightly rewrite the expression to an equivalent one, `radcan` succeeds. Applying `logcontract` also helps, as does setting the internal flag `?expsumsplit` to `false`:
~~~
(%i1)	X : 2^(log(3)/(log(2)-log(3)))-3^(log(3)/(log(2)-log(3))+1)$
(%i2)	radcan(X);
(%o2)	(%e^(-log(3)^2/(log(3)-log(2)))*(%e^(log(3)^2/(log(3)-log(2)))-3*2^(log(3)/(log(3)-log(2)))))/2^(log(3)/(log(3)-log(2)))
(%i3)	radcan(logcontract(X));
(%o3)	0
(%i4)	Y : 2^(log(3)/(log(2)-log(3)))-1/3^(log(2)/(log(3)-log(2)))$
(%i5)	radcan(Y);
(%o5)	0
(%i6)	radcan(X), ?expsumsplit:false;
(%o6)	0
~~~
Thanks to Richard Fateman for investigating.


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