-- Option variable: assume_pos Default value:
true and the sign of a parameter <x> cannot be determined from the current context or other considerations,
asksign (<x>) return
true. This may forestall some automatically-generated
asksign queries, such as may arise from
integrate or other computations.
By default, a parameter is <x> such that
symbolp (<x>) or
subvarp (<x>). The class of expressions considered parameters can be modified to some extent via the variable
asksign attempt to deduce the sign of expressions from the sign of operands within the expression. For example, if
b are both positive, then
a + b is also positive.
However, there is no way to bypass all
asksign queries. In particular, when the
asksign argument is a difference
<x> - <y> or a logarithm
asksign always requests an input from the user, even when
assume_pos_pred is a function which returns
true for all arguments.
There are also some inexact matches for
?? assume_pos to see them.
(%o1) true (%i2)