HANDBOOK / GENTLE PRIMER /

# Control Structures

So far, rules were the only mechanism for describing decisions. When two cases had to be described, two different rules were required. When a local decision was necessary inside a rule body, a new predicate was introduced to handle this.

In this section, we introduce further constructs to deal with decisions.

- The Alternative Statement
- Dataflow
- The Predicate `where`
- Disjunctions
- The Conditional Statement
- Using Alternative and Conditional Statements