Turing Machines

Creating a new Automaton

To create a new Turing machine, look for the list of possible formal language types and click on Turing Machine.

You will see a split screen with a drawing area on the left and an editing area to the right.

Creating & Editing States

The procedure for creating and editing states is the same as for finite automata.

Creating & Editing Transitions

The procedure for creating and editing states is very similar to the procedure for finite automata.

The difference is the format of the label. Each transition label has the form

input/output,direction

where

• input is a single input character to be matched from the tape. This may be any alphanumeric.
• output is the character to be written to the tape, replacing the matched input.
• direction is one of 'L', 'R', or 'S', indicating that the tape head should shift one position to the Left, one position to the Right, or stay Stationary.

Shortcuts are also available:

• @ denotes an empty cell.
• !x, in the input or top, means "any character except x".
• ~ means "any character" when occurring in the input, and
  means "same as the input character" in the top or the push strings.
• a,b, ...}v, in the input, means to match any of the possible input characters on the left of the '}', storing the matched character in a "variable" 'v'.
  • The variable name can be any alphabetic character not used in the TM alphabet.
  • Any subsequent mentions of that variable name in input or output of other transitions will be replaced by the stored character.