introduction to the z example two. 2 write z specifications for the birthday book problem the...

Introduction to the ZExample Two

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Write Z specifications for the Birthday Book Problem

The Birthday Book system keeps track of people’s birthdays. It allows you to add and search for birthdays. Also, it issues reminders.

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The Z specification should include:

Given Sets State Schema Initial State Operations

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The Birthday Book Z Specification

1. Given Sets [NAME,DATE]

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2. State definition

BirthDayBook

known: ℙ NAME

Birthday: NAME ⇸ DATE

known = dom birthday

Notation: D ⇸ R

⇸ ↦ Ξ ∀ × → Δ ≠ ∧ ∨ ∉ ∈ ∅ ∃ ℤ ℕ ℙ ℝ ≙

Birthday Function: Example

known = {Ahmed, Zaid, Qais} birthday = {Ahmed ↦ 17-Ram, Zaid ↦ 27-Sha, Qais ↦ 10-Raj}

The notation x ↦ y

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3. Initial State BirthDayInit

BirthdayBook

known = Ø

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Operations

1. Add birthday2. Find birthday3. Remind

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4. Operations (AddBirthday) AddBirthday BirthdayBook

name? : NAMEdate?: DATE

name? knownknown’= known {name?}birthday’ = birthday {name? ↦ date?}

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4. Operations (FindBirthday) FindBirthday BirthdayBook

name? : NAMEdate!: DATE

name? known

date! = birthday(name?)

X

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4. Operations (Remind) Remind BirthdayBook

cards! : ℙ NAMEtoday?: DATE

cards!= {n: known | birthday (n) = today!}

X

introduction to the z example two. 2 write z specifications for the birthday book problem the...

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