* changed queue to set in AC3

Changed queue to set in AC3 (as in the pseudocode of the original algorithm) to reduce the number of consistency-check due to the redundancy of the same arcs in queue. For example, on the harder1 configuration of the Sudoku CSP the number consistency-check has been reduced from 40464 to 12562!

* re-added test commented by mistake

* added the mentioned AC4 algorithm for constraint propagation

AC3 algorithm has non-optimal worst case time-complexity O(cd^3 ), while AC4 algorithm runs in O(cd^2) worst case time

* added doctest in Sudoku for AC4 and and the possibility of choosing the constant propagation algorithm in mac inference

* removed useless doctest for AC4 in Sudoku because AC4's tests are already present in test_csp.py

* added map coloring SAT problems

* fixed typo errors and removed unnecessary brackets

* reformulated the map coloring problem

* Revert "reformulated the map coloring problem"

This reverts commit 20ab0e5afa238a0556e68f173b07ad32d0779d3b.

* Revert "fixed typo errors and removed unnecessary brackets"

This reverts commit f743146c43b28e0525b0f0b332faebc78c15946f.

* Revert "added map coloring SAT problems"

This reverts commit 9e0fa550e85081cf5b92fb6a3418384ab5a9fdfd.

* Revert "removed useless doctest for AC4 in Sudoku because AC4's tests are already present in test_csp.py"

This reverts commit b3cd24c511a82275f5b43c9f176396e6ba05f67e.

* Revert "added doctest in Sudoku for AC4 and and the possibility of choosing the constant propagation algorithm in mac inference"

This reverts commit 6986247481a05f1e558b93b2bf3cdae395f9c4ee.

* Revert "added the mentioned AC4 algorithm for constraint propagation"

This reverts commit 03551fbf2aa3980b915d4b6fefcbc70f24547b03.

* added map coloring SAT problem

* fixed build error

* Revert "added map coloring SAT problem"

This reverts commit 93af259e4811ddd775429f8a334111b9dd9e268c.

* Revert "fixed build error"

This reverts commit 6641c2c861728f3d43d3931ef201c6f7093cbc96.

* added map coloring SAT problem

* removed redundant parentheses

* added Viterbi algorithm

* added monkey & bananas planning problem

* simplified condition in search.py

* added tests for monkey & bananas planning problem

* removed monkey & bananas planning problem

* Revert "removed monkey & bananas planning problem"

This reverts commit 9d37ae0def15b9e058862cb465da13d2eb926968.

* Revert "added tests for monkey & bananas planning problem"

This reverts commit 24041e9a1a0ab936f7a2608e3662c8efec559382.

* Revert "simplified condition in search.py"

This reverts commit 6d229ce9bde5033802aca29ad3047f37ee6d870d.

* Revert "added monkey & bananas planning problem"

This reverts commit c74933a8905de7bb569bcaed7230930780560874.

* defined the PlanningProblem as a specialization of a search.Problem & fixed typo errors

* fixed doctest in logic.py

* fixed doctest for cascade_distribution

* added ForwardPlanner and tests

* added __lt__ implementation for Expr

* added more tests

* renamed forward planner

* Revert "renamed forward planner"

This reverts commit c4139e50e3a75a036607f4627717d70ad0919554.

* renamed forward planner class & added doc

* added backward planner and tests

* fixed mdp4e.py doctests

* removed ignore_delete_lists_heuristic flag

* fixed heuristic for forward and backward planners

* added SATPlan and tests

* fixed ignore delete lists heuristic in forward and backward planners

* fixed backward planner and added tests

* updated doc

* added nary csp definition and examples

* added CSPlan and tests

* fixed CSPlan

* added book's cryptarithmetic puzzle example

* fixed typo errors in test_csp

* fixed #1111

* added sortedcontainers to yml and doc to CSPlan

* added tests for n-ary csp

* fixed utils.extend

* updated test_probability.py

* converted static methods to functions

* added AC3b and AC4 with heuristic and tests

* added conflict-driven clause learning sat solver

* added tests for cdcl and heuristics

* fixed probability.py

* fixed import

* fixed kakuro

* added Martelli and Montanari rule-based unification algorithm

* removed duplicate standardize_variables

* renamed variables known as built-in functions

* fixed typos in learning.py

* renamed some files and fixed typos

* fixed typos

* fixed typos

* fixed tests

* removed unify_mm

* remove unnecessary brackets

* fixed tests

* moved utility functions to utils.py

* fixed typos

* moved utils function to utils.py, separated probability learning classes from learning.py, fixed typos and fixed imports in .ipynb files

* added missing learners

* fixed Travis build

* fixed typos

* fixed typos

* fixed typos

* fixed typos

* fixed typos in agents files

* fixed imports in agent files

* fixed deep learning .ipynb imports

* fixed typos

* added SVM

* added .ipynb and fixed typos

* adapted code for .ipynb

* fixed typos

* updated .ipynb

* updated .ipynb

* updated logic.py

* updated .ipynb

* updated .ipynb

* updated planning.py

* updated inf definition

* fixed typos

* fixed typos

* fixed typos

* fixed typos

* Revert "fixed typos"

This reverts commit 658309d32a3baa0a6b8aac247c0d4ae39cf39ea4.

* Revert "fixed typos"

This reverts commit 08ad6603ce7b6a6442a28bc0a07c46fa25af3452.

* fixed typos

* fixed typos

* fixed typos

* fixed typos

* fixed typos and utils imports in *4e.py files

* fixed typos

* fixed typos

* fixed typos

* fixed typos

* fixed import

* fixed typos

* fixed typos

* fixd typos

* fixed typos

* fixed typos

* updated SVM

* added svm test

* fixed SVM and tests

* fixed some definitions and typos

* fixed svm and tests

* added SVMs also in learning4e.py

* fixed inf definition

* fixed .travis.yml

* fixed .travis.yml

* fixed import

* fixed inf definition

* replaced cvxopt with qpsolvers

* replaced cvxopt with quadprog

* fixed some definitions

* fixed typos and removed unnecessary tests

* replaced quadprog with qpsolvers

* fixed extend in utils

* specified error type in try-catch block

* fixed extend in utils

* fixed typos

* fixed learning.py

* fixed doctest errors

* added comments

* removed unnecessary if condition

* updated learning.py

* fixed imports

* removed unnecessary imports

* fixed keras imports

* fixed typos

* fixed learning_curve

* added comments

* fixed typos

* removed inf and isclose definition from utils and replaced with numpy.inf and numpy.isclose

* fixed doctests

* fixed numpy imports

* fixed superclass call

* removed utils import from 4e py file

* removed unnecessary norm function in utils and fixed Activation definition