modification of new assumptions
do not conclude if there is no precision
modify AskPositiveHandler.log

Also changed ~negative to nonnegative since ~negative does
not imply that the number is even real: it could be imaginary
or positive or zero. nonnegative implies that the number is
real and is not 0 or negative (and that's what the test in Add
is looking for).
code quality: check for duplicate test_ functions