commit d26aadceaca153d24cc9e0d66c7997ef5067a9a5
Merge: ff1b343 af1e094
Author: Christopher Smith <smichr@gmail.com>
Date:   Wed Mar 14 09:13:38 2012 -0700

    Merge pull request #1120 from mrocklin/3143_matrixbase_identity

    added is_square check to is_identity

commit ff1b343b1f97291d1b5c2948fa86b7df00f4b485
Merge: 1834e96 9d2d54c
Author: Christopher Smith <smichr@gmail.com>
Date:   Wed Mar 14 05:28:09 2012 -0700

    Merge pull request #1058 from smichr/non-recursive

    Non recursive is_positive and is_negative for Mul

commit 9d2d54cf52e4231db9462a52dd239bc219bd50bb
Author: Chris Smith <smichr@gmail.com>
Date:   Sun Mar 11 17:53:37 2012 +0545

    move is_zero test higher in is_positive|negative logic

        is_nonpositive catches a zero so any zero factor never
        provided a quick exit for is_positive and is_negative,
        so the is_zero test was moved before that test and covereage
        checked to see that that is now covered.

commit 98ca2e260b2fb81078439eb97dc297c0456fa462
Author: Chris Smith <smichr@gmail.com>
Date:   Sat Mar 10 01:02:14 2012 +0545

    simplify Mul.is_(positive|negative) code; add docstrings

commit 8defcf4557a2519fbfdad514032c3b2e14ae1a2c
Author: Chris Smith <smichr@gmail.com>
Date:   Sat Feb 18 09:49:48 2012 +0545