From WeBWorK

MathObjects reduces mathematical expressions according to a set of reduction rules. These control which expressions are reduced. Reductions can be turned off in two ways:

For all subsequent reduce operations in the problem:

Context()->reduction->set('x/1'=>0);

For a single reduction:

$f->reduce('x/1'=>0);

Rule	Reduction
0><x	0
0-x	-x
0/x	0
0.x	0
0*x	0
0+x	x
1^x	1
1*x	x
-a-bi	-(a+bi)
fn*x	x*fn
-n	If the number is negative, factor it out and try using that in the reductions of the parent objects.
V_n	Select the nth item of V.
x^0	1
x><0	0
x-0	x
x.0	0
x*0	0
x+0	x
-(-x)	x
+x	x
x^(-1)	1/x
x/1	x
x*1	x
-x=n	x=-n
x*n	n*x
-x=-y	x=y
(-x)><y	x><-y
(-x)-y	-(x+y)
(-x)/y	-(x/y)
(-x).y	-(x.y)
(-x)*y	-(x*y)
(-x)+y	y-x
x><(-y)	-(x><y)
x-(-y)	x+y
x/(-y)	-(x/y)
x.(-y)	-(x.y)
x*(-y)	-(x*y)
x+(-y)	x-y