Predicates and Constraints
Validation of a contract’s state occurs through the satisfaction of one of the contract's predicates.
- Think of predicates as "pathways to validity." For a contract to be satisfied (and for its state to be updated), one of its predicates must be met.
- A predicate consists of one or more constraints. A constraint is a boolean expression that must evaluate to
Truefor the predicate to be satisfied.
From a code organization perspective, predicates might look like functions, but there's a key difference: predicates are not called like functions. Instead, they are targets that individual solutions attempt to satisfy.