This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.

# Cancel

 Cancel[expr]cancels out common factors in the numerator and denominator of expr.
• Cancel cancels out the greatest common divisor of the numerator and denominator.
• Cancel[expr, Trig->True] treats trigonometric functions as rational functions of exponentials, and manipulates them accordingly.
• Cancel automatically threads over lists, as well as equations, inequalities and logic functions.
Cancel common factors:
Cancel common factors:
 Out[1]=
 Out[2]=
 Scope   (2)
Cancel threads over Boolean combinations of equations and inequalities:
 Options   (3)
By default, Cancel treats algebraic numbers as independent variables:
With Extension, Cancel recognizes algebraically dependent coefficients:
Over the rational numbers the numerator and the denominator have no common factors:
Over the integers modulo 2, the denominator divides the numerator:
By default, Cancel treats trigonometric functions as independent variables:
With Trig->True, Cancel recognizes dependencies between trigonometric functions:
Cancel cancels common factors between numerators and denominators:
Together combines terms over a common denominator and cancels common factors: