https://github.com/jes/ttgen

Truth-table generator for boolean logic expressions.
https://github.com/jes/ttgen

Last synced: over 1 year ago
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Truth-table generator for boolean logic expressions.

• Host: GitHub
• URL: https://github.com/jes/ttgen
• Owner: jes
• Created: 2010-10-07T15:14:55.000Z (almost 16 years ago)
• Default Branch: master
• Last Pushed: 2011-07-30T13:21:55.000Z (about 15 years ago)
• Last Synced: 2025-03-29T04:51:12.178Z (over 1 year ago)
• Language: C
• Homepage:
• Size: 113 KB
• Stars: 5
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README

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README

          
ttgen is a program to generate truth tables for boolean logic expressions.

Compile it with:

$ cc -o ttgen ttgen.c

When you run the program, you will receive no output initally. You are expected

to enter a boolean expression, for example:

  X & Y & !Z

And ttgen will respond with the truth table:

  X Y Z 

  T T T  F

  F T T  F

  T F T  F

  F F T  F

  T T F  T

  F T F  F

  T F F  F

  F F F  F

Exit ttgen by giving EOF on stdin (usually with ^D), or by killing the program

in any way (e.g. with ^C).

Operators available:

Symbol   Synonym   Operator

!        NOT       Logical negation

|        OR        Logical or

&        AND       Logical and

^        XOR       Logical xor

         NAND      Logical nand (NOT (X AND Y))

         NOR       Logical nor (NOT (X OR Y))

->       IMP       Logical implication ((NOT A) OR B)

=        EQU       Logical equivalence

In addition, parentheses are supported and operator synonyms are case

insensitive.

Variable names may consist of letters, numbers, underscore and single quote(').

The latter is allowed so that variables like X' (X prime) may be used.

The variables are shown in the table in the order in which they appeared in

your expression. If you wish to change this order, you may use slashvars mode.

  /Z Y X

  X & Y & !Z

And ttgen responds with:

  Z Y X 

  T T T  F

  F T T  T

  T F T  F

  F F T  F

  T T F  F

  F T F  F

  T F F  F

  F F F  F

Slashvars mode is easiest to understand (and is, in fact, implemented) as if

the variables given on the slashvar line were present at the start of the

expression. This means that if you miss some variables out in your slashvar

line they can still be used with no problem in the expression, and also that if

some variables in the slashvar line are not present in the expression they will

still appear in the truth table:

  /X Y

  Y & Z

ttgen responds:

  X Y Z 

  T T T  T

  F T T  T

  T F T  F

  F F T  F

  T T F  F

  F T F  F

  T F F  F

  F F F  F

Slashvars mode is entered when a / is encountered as the first token on a line,

and all variables are immediately cleared. This means that if you specify two

slashvar lines without an expression in between, only the second slashvar line

will actually apply:

  /X Y Z

  /Y Z

ttgen responds:

  Y Z 

  T T  T

  F T  F

  T F  F

  F F  F

Note no X variable in the output.