Compare a and b lexicographically by applying each fun to them. For unary functions compares fun(a) < fun(b).
Checks if both ranges are permutations of each other.
Order a and b lexicographically by applying each fun to them. For unary functions compares fun(a) < fun(b).
Returns one of a collection of expressions based on the value of the switch expression.
Some additional alogorithm functions.