OCL25 — Are failures invalid?

OCL is an executable specification language that uses "invalid" as its exception handling mechanism for untoward execution, which clearly includes deterministic internal program control faults:

• divide by zero
• null-navigation
• ordered collection index out of bounds
  Does this behavior also include non-deterministic external problems:
• network/disk access failure
• stack overflow
• tooling malfunction

Without an answer to this question, it i impossible to know whether e.g. "aSequence->includes->last()" can be optimized to "x" or not. Is it necessary to fully evaluate aSequence, perhaps run out of memory, in order to incur an external issue that influences an evaluation?