Removal of Unit Productions

The removal of unit productions involves two steps:

1. Visualizing the unit productions
2. Removing the unit productions

Each step must be done in order. Below is a picture of the unit production removal window:

Step 1: Visualizing the unit productions
When you press the "Visualize Productions" button, the visualization window is invoked. In order to visualize unit productions, a dependency diagram must be created. Each arrow represents a unit production from one variable to another variable.

Step 2: Modifying the grammar to remove the unit productions
Modifying the grammar involves removing and adding new productions. In the left pane, the grammar that is being modified is shown. In the right pane, the initial grammar is provided for reference. Four operations can be performed when modifying a grammar:

• Adding New Rules - To add a new rule, enter the production in the input fields then press the "Add New Rule" button
• Remove Rules - To remove rules from the production, highlight the rules that are to be removed (you can select multiple rules) by clicking on them with the left mouse button. Then, press the "Remove Selected Rule(s)" button.
• Checking the Answer - press the "Check Answer" button to ensure that the modifications are correct.
• Showing the Answer - press the "Show Answer" if you just want to see the resulting grammar and move on.

Removing unit productions involves removing the productions that are unit productions, then adding new productions that exclude the productions that are unit productions. For example, if a grammar contained the rules:

A->C
B->cAd
C->a

Then you would remove A->C and add A->a.

Step 3: Continuing
To continue on to the next transformation press the "Next Transformation" button. If you want to parse the grammar to see the derivation of an acceptance string then press the "Parse" button.