Added search utility and boolean algebra for representing predicate l…

…ogic

Signed-off-by: Ayush Joshi <[email protected]>

ai/__init__.py

@@ -21,8 +21,11 @@
 from bs4 import BeautifulSoup
 from urllib.parse import urlparse
 
-from .stats import corrcoef
+from .stats import (cov, corrcoef)
 from .mathematical_functions import proportion
+from .boolalg import (
+  Sentence, Symbol, Not, And, Or, Implication, Biconditional, model_check
+)
 
 from .neighbors import KNeighborsClassifier
 from .naive_bayes import GaussianNaiveBayes
@@ -76,7 +79,6 @@ def _PreprocessReadme(fpath: Union[str, pathlib.Path]) -> str:
   'Introduction-to-ML.md',
   'Descending-into-ML.md',
   'Reducing-Loss.md',
-  'Introduction-to-TensorFlow.md',
   'Generalization.md',
   'Training-and-Test-Sets.md',
   'Validation-Set.md',

ai/boolalg/__init__.py

@@ -0,0 +1,37 @@
+# Copyright 2023 The AI Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# pylint: disable=too-many-function-args, invalid-name, missing-module-docstring
+# pylint: disable=missing-class-docstring
+
+"""Symbolic Propositional Logic for Knowledge representation.
+
+>>> from ai import (Symbol, And, Or, Not, Implication)
+...
+>>> rain = Symbol("rain")
+>>> hagrid = Symbol("hagrid")
+>>> dumbledore = Symbol("dumbledore")
+...
+>>> knowledge = And(
+>>>     Implication(Not(rain), hagrid),
+>>>     Or(hagrid, dumbledore),
+>>>     Not(And(hagrid, dumbledore)),
+>>>     dumbledore
+>>> )
+...
+>>> print(model_check(knowledge, rain))
+"""
+
+from .logic import (
+  Sentence, Symbol, Not, And, Or, Implication, Biconditional, model_check
+)