[Maxima-bugs] [ maxima-Bugs-1868939 ] bfloat with factorials adds spurious factor

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Bugs item #1868939, was opened at 2008-01-10 18:10
Message generated for change (Comment added) made by rtoy
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Category: Lisp Core - Simplification
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Stavros Macrakis (macrakis)
Assigned to: Nobody/Anonymous (nobody)
Summary: bfloat with factorials adds spurious factor

Initial Comment:
bfloat(1.0b0!/2.0b0!) returns 1.0b0*1.0b0!/2.0b0! 

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>Comment By: Raymond Toy (rtoy)
Date: 2008-01-15 12:20

Message:
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user_id=28849
Originator: NO

I think this is basically caused by the rule that bigfloats are
contagious.  1b0*x remains 1b0*x.

In particular timesbigfloat produces 1b0*(1b0!/2b0!).  This happens
because it splits the terms into bigfloats and non-bigfloats, multiplies
these together and then multiplies the two parts together.  The simplifier
doesn't make this simpler because it thinks 1b0! isn't a bigfloat.

It's unfortunate that 1b0! isn't converted to a bigfloat right away. I
think bffac and/or cbbfac should be incorporated into the simplifier for
factorial.

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