Editing Curry (programming language) (section)

===Strategies===
Due to the absence of side effects, a functional logic program can be executed with different strategies. To evaluate expressions, Curry uses a variant of the ''needed narrowing'' strategy which combines [[lazy evaluation]] with non-deterministic search strategies. In contrast to Prolog, which uses backtracking to search for solutions, Curry does not fix a particular search strategy. Hence, there are implementations of Curry, like [http://www-ps.informatik.uni-kiel.de/kics2/ KiCS2], where the user can easily select a search strategy, like [[depth-first search]] (backtracking), [[breadth-first search]], iterative deepening, or parallel search.