Programmers may deliberately obfuscate code to conceal its purpose ( security through obscurity ) or its logic, in order to prevent tampering, deter reverse engineering, or as a puzzle or recreational challenge for someone reading the source code.

A logic puzzle is a puzzle deriving from the mathematics field of deduction.

Example logic puzzle grid, with the information that only Simon is 15 and Jane does not like green filled in.

Another form of logic puzzle, popular among puzzle enthusiasts and available in magazines dedicated to the subject, is a format in which the set-up to a scenario is given, as well as the object ( for example, determine who brought what dog to a dog show, and what breed each dog was ), certain clues are given (" neither Misty nor Rex is the German Shepherd "), and then the reader fills out a matrix with the clues and attempts to deduce the solution.

Common in logic puzzle magazines are derivatives of the logic grid puzzle called " table puzzles " that are deduced in the same manner as grid puzzles, but lack the grid either because a grid would be too large, or because some other visual aid is provided.

* Pirate game, a puzzle of logic and mathematics

She advances through the labyrinth alone and overcomes a series of obstacles during her journey, including a Knights and Knaves logic puzzle, before eventually trapping herself in an oubliette.

The following is a Prolog program that solves the classical alphametic puzzle SEND + MORE = MONEY in constraint logic programming:

* Puzzle iT web site by Dr. Florian Radut A British-Romanian puzzle collection: mechanical puzzles, 2D puzzles, 3D puzzles, logic games and anagram puzzles, some of them used in TV Game-Shows, SMS contests and online contests.

In the English language, the expression " Japanese puzzle " usually refers to logic puzzles, which ( at least in the past ) have been more popular in Japan than in the West, where word games dominate.

Knights and Knaves is a type of logic puzzle.

These types of puzzles were a major inspiration for what has become known as " the hardest logic puzzle ever ".

* Make 10: A Journey of Numbers ( a puzzle / logic style adventure game )

He wrote a paper on " the hardest logic puzzle ever "— one of many puzzles created by Raymond Smullyan.

The hardest logic puzzle ever.

* Pearls Before Swine, a puzzle / logic game using the Nim format

The prisoners and hats puzzle is an induction puzzle ( a kind of logic puzzle ) that involves reasoning about the actions of other people, drawing in aspects of Game theory sometimes called the hierarchy of beliefs.

The logic of creating a strong, balanced, competitive two-system railroad service in the East is so obvious that B. & O. was publicly committed to the approach outlined here.

Since Russian was being spoken instead of Spanish, there is no violation of artistry or logic here.

His works contain the earliest known formal study of logic, which was incorporated in the late 19th century into modern formal logic.

With the Prior Analytics, Aristotle is credited with the earliest study of formal logic, and his conception of it was the dominant form of Western logic until 19th century advances in mathematical logic.

The mechanical and logic design was worked out by Dr. Atanasoff over the next year.

Alan ’ s philosophy was a sort of mixture of Aristotelian logic and Neoplatonic philosophy.

The display logic and resulting display ' snow ' was irritating, as was the missing lower case support, the CPU speed could be improved, the quality and layout of the keyboard was bothersome, and the floppy disk capacity and reliability was low.

More ambitious was the Logic Theory Machine, a deduction system for the propositional logic of the Principia Mathematica, developed by Allen Newell, Herbert A. Simon and J. C. Shaw.

As the user stories pass their acceptance criteria, the business owners can be sure of the fact that the developers are progressing in the right direction about how the application was envisaged to work and so it's essential that these tests include both business logic tests as well as UI validation elements ( if need be ).

If, for instance, an addition operation was requested, the arithmetic logic unit ( ALU ) will be connected to a set of inputs and a set of outputs.

The first intermolecular logic gate using SWCNT FETs was made in 2001.

In 1879, Peirce was appointed Lecturer in logic at the new Johns Hopkins University, which was strong in a number of areas that interested him, such as philosophy ( Royce and Dewey did their PhDs at Hopkins ), psychology ( taught by G. Stanley Hall and studied by Joseph Jastrow, who coauthored a landmark empirical study with Peirce ), and mathematics ( taught by J. J. Sylvester, who came to admire Peirce's work on mathematics and logic ).

He was put under the care of a " former mule-driver " to keep him disciplined, under the logic that his condition was due to laziness and a lack of will-power.

For instance, a professor of formal logic called Chin Yueh-lin – who was then regarded as China ’ s leading authority on his subject – was induced to write: “ The new philosophy Marxism-Leninism, being scientific, is the supreme truth ”.

Aristotle's writings were the first to create a comprehensive system of Western philosophy, encompassing morality, aesthetics, logic, science, politics, and metaphysics.

The first three treatises form the core of the logical theory stricto sensu: the grammar of the language of logic and the correct rules of reasoning.

The Analytical Engine incorporated an arithmetic logic unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first design for a general-purpose computer that could be described in modern terms as Turing-complete.

As an example of a conditional proof in symbolic logic, suppose we want to prove A → C ( if A, then C ) from the first two premises below:

The first mainframe computers, using firstly vacuum tubes and later transistors in the logic circuits, appeared in the 1940s and 1950s.

All of the logic functions of a calculator had been squeezed into the first " Calculator on a chip " integrated circuits in 1971, but this was leading edge technology of the time and yields were low and costs were high.

Hilbert is known as one of the founders of proof theory and mathematical logic, as well as for being among the first to distinguish between mathematics and metamathematics.

A basic objective of the first normal form defined by Codd in 1970 was to permit data to be queried and manipulated using a " universal data sub-language " grounded in first-order logic.

Later, in the first volume of his Logical Investigations, the Prolegomena of Pure Logic, Husserl, while attacking the psychologistic point of view in logic and mathematics, also appears to reject much of his early work, although the forms of psychologism analysed and refuted in the Prolegomena did not apply directly to his Philosophy of Arithmetic.

The first prejudice is the supposition that logic is somehow normative in nature.

There are two key parts of first order logic.

A few years later, Peano published his first book dealing with mathematical logic.

* IBM RAMAC 305 ( vacuum tube logic, first computer with disk storage ; see: Early IBM disk storage )

In 1972, Intel launched the 8008, the first 8-bit microprocessor .< ref > using enhancement load PMOS logic ( demanding 14V, achieving TTL-compatibility by having V < sub > CC </ sub > at + 5V and V < sub > DD </ sub > at-9V )</ ref > It implemented an instruction set designed by Datapoint corporation with programmable CRT terminals in mind, that also proved to be fairly general purpose.

That is, the " middle " position, that Socrates is neither mortal nor not-mortal, is excluded by logic, and therefore either the first possibility ( Socrates is mortal ) or its negation ( it is not the case that Socrates is mortal ) must be true.

However, the first proposal to use the clausal form of logic for representing computer programs was made by Cordell Green ( 1969 ).

Although it was based on the proof methods of logic, Planner, developed at MIT, was the first language to emerge within this proceduralist paradigm 1969.

* Shawn Hedman, A first course in logic: an introduction to model theory, proof theory, computability, and complexity, Oxford University Press, 2004, ISBN 0-19-852981-3.

Physicist Lee Smolin writes in Three Roads to Quantum Gravity that topos theory is " the right form of logic for cosmology " ( page 30 ) and " In its first forms it was called ' intuitionistic logic '" ( page 31 ).

Semantics of Business Vocabulary and Business Rules ( SBVR ) is a landmark for the OMG, the first OMG specification to incorporate the formal use of natural language in modeling and the first to provide explicitly a model of formal logic.

* Prolog, designed in 1972, was the first logic programming language.

Prolog was one of the first logic programming languages, and remains the most popular among such languages today, with many free and commercial implementations available.