Performance Tuning
REPL use Display
(+) Operator for Character & String type
Integer -> Flonum -> Rational
Flonum -> Integer -> Rational
Integer -> Rational -> Rational
Rational -> Integer -> Rational
Flonum -> Rational -> Rational
Rational -> Flonum -> Rational
Merge branch 'evaluation'

* evaluation:
  (+) Operator for Character & String type Integer -> Flonum -> Rational Flonum -> Integer -> Rational Integer -> Rational -> Rational Rational -> Integer -> Rational Flonum -> Rational -> Rational Rational -> Flonum -> Rational
  REPL use Display
  Performance Tuning