Include ()'s in latex conversion of Implies
additional test of latex Implies grouping
fix sign to recognize sqrt with negative arg
watch for sign change from I in sign()
simplify sign code, watch for recursion
add sign.is_(nonnegative|nonpositive)
Change Kane and Lagrange attributes

- KanesMethod has q and u as full attributes
- LagrangesMethod has q as a full attribute
- KanesMethod now stores forcelist and bodylist as attributes
Deprecate set.is_real property, use set.is_subset(Reals) instead

fixes #6212
Improve Mul._eval_is_rational: add check for zero

fixes #8008
minor docstring edit [skip ci]
expand sign docstring to reflect its complex nature
bug fix in dup_zz_zassenhaus for issue 8037
Add @property to some attributes

- KanesMethod.q, .u, .forcelist, and .bodylist are all read-only now
- LagrangesMethod.q, .u, and .forcelist are all read-only now
Merge pull request #8038 from pernici/factor4

bug fix in dup_zz_zassenhaus for issue 8037

fixes #8037
Merge pull request #8014 from zanzibar7/bool_latex

Include ()'s in latex conversion of Implies
Fix is_rational helper for exp_polar(0)

fixes #8008
_minpoly_compose: Change incorrect is_rational tests to is_Rational

We need this, as later we use .p/q properties.
simplify Mul._eval_is_negative routine
simplify Mul._eval_is_even
Fixed typos in four files