Optimizer: addition
Optimizer: multiplication to power
Optimizer: constants multiplication
multiplying by zero
Optimizer: more tests
Optimizer: check for invalid input
Optimizer: division normalization
Optimizer: fractions reduction init
Optimizer: fractionsReduction
Optimizer: fraction constants reductions init
Optimizer: fractions reduce refactoring
Optimizer: wip
Optimizer: fraction constants reduction
Merge pull request #10 from summeragain/master

Add some tests
Optimizer: grouping init
Optimizer: grouping. issue #8
Optimizer: common denominator optimization impl - #9
Merge pull request #11 from denzp/optimizer

Optimizer
fix for #7
unary minus init