Procedure

Getting Started

The simulation interface consists of three main components:

1. Grammar Control Panel: Contains buttons to change grammars, input strings, and manage the derivation process
2. Parse Tree Visualization: An interactive visual representation of the derivation tree being constructed
3. Derivation Steps Panel: Shows the step-by-step derivation sequence as you build the parse tree

Step-by-Step Instructions

1. Selecting a Grammar

Click the "Change Grammar" button to cycle through the three available grammars. Each grammar has a description explaining the language it generates. The current grammar's description is displayed above the parse tree, along with its production rules.

2. Choosing Input Strings

Click the "Change Input" button to cycle through different pre-configured target strings for the current grammar. Each grammar comes with multiple example strings that can be generated using the production rules.

3. Understanding the Interface

• Start Symbol: The root node of the parse tree, typically labeled with the grammar's start symbol
• Non-terminal Nodes: Displayed in red when they can be expanded further
• Terminal Nodes: Displayed in blue when they represent final symbols
• Target String: Shows the string you need to generate through the derivation
• Production Rules: Interactive buttons that apply specific grammar rules

4. Building Parse Trees Interactively

Selecting Nodes for Expansion

• Red nodes indicate non-terminal symbols that can be expanded
• Click on a red node to select it for expansion
• Selected nodes are highlighted to show which node will be expanded next

Applying Production Rules

After selecting a node:

• Production rule buttons appear below the parse tree
• Click on a production rule button to apply that rule to the selected node
• The selected node will expand according to the chosen production rule
• New child nodes are automatically created and positioned in the tree

5. Managing the Derivation Process

Reset Tree

Click the "Reset Tree" button to return the parse tree to its initial state with only the start symbol.

Show Hint

Click the "Show Hint" button to receive guidance on the next appropriate step in the derivation process.

Derivation Steps Tracking

The right panel automatically tracks each step of your derivation:

• Shows the current string form at each step
• Displays which production rule was applied
• Highlights the most recent step in the derivation

6. Understanding Results

Continue expanding non-terminal nodes until no red nodes remain. The derived string (reading the leaves from left to right) should match the target string to complete the derivation successfully.