**What is Fuzzy Set ?**

Fuzzy refers to something that is unclear or vague . Hence, Fuzzy Set is a Set where every key is associated with value, which is between 0 to 1 based on the certainity .This value is often called as degree of membership. Fuzzy Set is denoted with a Tilde Sign on top of the normal Set notation.

**Operations on Fuzzy Set with Code :**

**1. Union :**

Consider 2 Fuzzy Sets denoted by A and B, then let’s consider Y be the Union of them, then for every member of A and B, Y will be:

degree_of_membership(Y)= max(degree_of_membership(A), degree_of_membership(B))

**EXAMPLE :**

## Python3

`# Example to Demonstrate the ` `# Union of Two Fuzzy Sets` `A ` `=` `dict` `()` `B ` `=` `dict` `()` `Y ` `=` `dict` `()` ` ` `A ` `=` `{` `"a"` `: ` `0.2` `, ` `"b"` `: ` `0.3` `, ` `"c"` `: ` `0.6` `, ` `"d"` `: ` `0.6` `}` `B ` `=` `{` `"a"` `: ` `0.9` `, ` `"b"` `: ` `0.9` `, ` `"c"` `: ` `0.4` `, ` `"d"` `: ` `0.5` `}` ` ` `print` `(` `'The First Fuzzy Set is :'` `, A)` `print` `(` `'The Second Fuzzy Set is :'` `, B)` ` ` ` ` `for` `A_key, B_key ` `in` `zip` `(A, B):` ` ` `A_value ` `=` `A[A_key]` ` ` `B_value ` `=` `B[B_key]` ` ` ` ` `if` `A_value > B_value:` ` ` `Y[A_key] ` `=` `A_value` ` ` `else` `:` ` ` `Y[B_key] ` `=` `B_value` ` ` `print` `(` `'Fuzzy Set Union is :'` `, Y)` |

**Output**

The First Fuzzy Set is : {'a': 0.2, 'b': 0.3, 'c': 0.6, 'd': 0.6} The Second Fuzzy Set is : {'a': 0.9, 'b': 0.9, 'c': 0.4, 'd': 0.5} Fuzzy Set Union is : {'a': 0.9, 'b': 0.9, 'c': 0.6, 'd': 0.6}

**2. Intersection :**

Consider 2 Fuzzy Sets denoted by A and B, then let’s consider Y be the Intersection of them, then for every member of A and B, Y will be:

degree_of_membership(Y)= min(degree_of_membership(A), degree_of_membership(B))

**EXAMPLE :**

## Python3

`# Example to Demonstrate` `# Intersection of Two Fuzzy Sets` `A ` `=` `dict` `()` `B ` `=` `dict` `()` `Y ` `=` `dict` `()` ` ` `A ` `=` `{` `"a"` `: ` `0.2` `, ` `"b"` `: ` `0.3` `, ` `"c"` `: ` `0.6` `, ` `"d"` `: ` `0.6` `}` `B ` `=` `{` `"a"` `: ` `0.9` `, ` `"b"` `: ` `0.9` `, ` `"c"` `: ` `0.4` `, ` `"d"` `: ` `0.5` `}` ` ` `print` `(` `'The First Fuzzy Set is :'` `, A)` `print` `(` `'The Second Fuzzy Set is :'` `, B)` ` ` ` ` `for` `A_key, B_key ` `in` `zip` `(A, B):` ` ` `A_value ` `=` `A[A_key]` ` ` `B_value ` `=` `B[B_key]` ` ` ` ` `if` `A_value < B_value:` ` ` `Y[A_key] ` `=` `A_value` ` ` `else` `:` ` ` `Y[B_key] ` `=` `B_value` `print` `(` `'Fuzzy Set Intersection is :'` `, Y)` |

**Output**

The First Fuzzy Set is : {'a': 0.2, 'b': 0.3, 'c': 0.6, 'd': 0.6} The Second Fuzzy Set is : {'a': 0.9, 'b': 0.9, 'c': 0.4, 'd': 0.5} Fuzzy Set Intersection is : {'a': 0.2, 'b': 0.3, 'c': 0.4, 'd': 0.5}

**3. Complement :**

Consider a Fuzzy Sets denoted by A , then let’s consider Y be the Complement of it, then for every member of A , Y will be:

degree_of_membership(Y)= 1 - degree_of_membership(A)

**EXAMPLE :**

## Python3

`# Example to Demonstrate the ` `# Difference Between Two Fuzzy Sets` `A ` `=` `dict` `()` `Y ` `=` `dict` `()` ` ` `A ` `=` `{` `"a"` `: ` `0.2` `, ` `"b"` `: ` `0.3` `, ` `"c"` `: ` `0.6` `, ` `"d"` `: ` `0.6` `}` ` ` `print` `(` `'The Fuzzy Set is :'` `, A)` ` ` ` ` `for` `A_key ` `in` `A:` ` ` `Y[A_key]` `=` `1` `-` `A[A_key]` ` ` `print` `(` `'Fuzzy Set Complement is :'` `, Y)` |

**Output**

The Fuzzy Set is : {'a': 0.2, 'b': 0.3, 'c': 0.6, 'd': 0.6} Fuzzy Set Complement is : {'a': 0.8, 'b': 0.7, 'c': 0.4, 'd': 0.4}

**4. Difference : **

Consider 2 Fuzzy Sets denoted by A and B, then let’s consider Y be the Intersection of them, then for every member of A and B, Y will be:

degree_of_membership(Y)= min(degree_of_membership(A), 1- degree_of_membership(B))

**EXAMPLE :**

## Python3

`# Example to Demonstrate the ` `# Difference Between Two Fuzzy Sets` `A ` `=` `dict` `()` `B ` `=` `dict` `()` `Y ` `=` `dict` `()` ` ` `A ` `=` `{` `"a"` `: ` `0.2` `, ` `"b"` `: ` `0.3` `, ` `"c"` `: ` `0.6` `, ` `"d"` `: ` `0.6` `}` `B ` `=` `{` `"a"` `: ` `0.9` `, ` `"b"` `: ` `0.9` `, ` `"c"` `: ` `0.4` `, ` `"d"` `: ` `0.5` `}` ` ` `print` `(` `'The First Fuzzy Set is :'` `, A)` `print` `(` `'The Second Fuzzy Set is :'` `, B)` ` ` ` ` `for` `A_key, B_key ` `in` `zip` `(A, B):` ` ` `A_value ` `=` `A[A_key]` ` ` `B_value ` `=` `B[B_key]` ` ` `B_value ` `=` `1` `-` `B_value` ` ` ` ` `if` `A_value < B_value:` ` ` `Y[A_key] ` `=` `A_value` ` ` `else` `:` ` ` `Y[B_key] ` `=` `B_value` ` ` `print` `(` `'Fuzzy Set Difference is :'` `, Y)` |

**Output **

The First Fuzzy Set is : {"a": 0.2, "b": 0.3, "c": 0.6, "d": 0.6} The Second Fuzzy Set is : {"a": 0.9, "b": 0.9, "c": 0.4, "d": 0.5} Fuzzy Set Difference is : {"a": 0.1, "b": 0.1, "c": 0.6, "d": 0.5}

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