# Rules: Groups and Conditions

Within the rules of each node, there is an expression editor.

This page will consider the following model:

There are three variables, A, B, and C, that can each be assigned with the values 1, 2, and 3.

Upon the ‘Path 1’ task block, we can apply a rule to tailor the generation of paths through the model. Each node can have multiple groups of conditions. Groups can be considered as a pair of parentheses in which a condition is contained.

There are a number of examples below that outline how to use the rules logic, conditions and groups.

**Example 1:**

The below rule translates to: *A=1 AND B=1 AND C=1 *

Note that in this case the AND/OR has no impact on the rule logic

Generates the following path:

**Example 2:**

The below rule translates to *(A=1 AND B=1 AND C=1) OR (A=3 AND B=3 AND C=3)*

Generates the following paths:

**Example 3:**

The below rule translates to (*A=1) AND (B=1) AND (C=1)*

Note that in this case selecting either AND/OR in the blue box has no impact on the rule logic

Generates the following path:

**Example 4:**

The below rule translates to: *(A=1) OR (B=1) OR (C=1)*

Generates 19 paths - every single path includes at least one of A=1, B=1, or C=1

**Example 5:**

The below rule translates to: ((A=1 AND B=1) OR (A=2 AND B=2)) OR ((A=3 AND B=3) OR (A=4 AND B=4))

In plain English, this means that A and B should always take the same value as each other, and all of the variations comes with C as it is unrestricted. Here’s an example test case:

TEST MODELLER TEST CASE GENERATION