A simple prefix notation integer calculator featuring history of previous results.
The calculator supports binary division, subtraction, multiplication
and addition using /, -, * and + respectively,
along with unary absolute value, factorial, negative,
predecessor, signum and successor using abs,
fact, neg, pred, sgn and succ respectively.
Previous results can be used by prefixing an index
in history with a $ like $0.
Inputting a sole value or variable will push it on top of history.
Binary operations:
# + 3 2
5
# * 6 9
54
# / $1 $0
10
# - $2 + $0 $1
-49
Pushing to history:
# 13
13
# $0
13
# $1
13
Unary operations:
# abs -5
5
# neg $0
-5
# sgn $1
-1
# pred 7
6
# succ $3
7
# fact $4
5040