 Cancellation, the consequence exclusively of a valid contract, cannot be claimed in all circumstances.It is an extraordinary remedy, available only if the breach is sufficiently serious or material—unless the parties have provided a cancellation clause (a "lex commissoria") in the agreement, in which case the agreement takes precedence over common-law rules.If the breach is minor, and there is no "lex commissoria", the innocent party can always rely on specific performance and claim for damages.