Added some rules to IMPLICIT list.

src/rules/precedences.py

@@ -4,7 +4,8 @@ from .numerics import reduce_fraction_constants
 from .logarithmic import factor_in_exponent_multiplicant, \
         factor_out_exponent, raised_base
 from .derivatives import chain_rule
-from .negation import double_negation
+from .negation import double_negation, negated_factor, negated_nominator, \
+        negated_denominator
 
 # Functions to move to the beginning of the possibilities list. Pairs of within
 # the list itself are compared by their position in the list: lower in the list
@@ -45,5 +46,8 @@ LOW = dict([(h, i) for i, h in enumerate(LOW)])
 # List of implicit rules. Implicit rules are condidererd trivial and are
 # therefore not printed in verbose rewrite_all mode
 IMPLICIT_RULES = [
+        negated_factor,
         double_negation,
+        negated_nominator,
+        negated_denominator,
         ]