The argument's own ID.
The conclusion premise ID, if set.
OptionalisWhether the argument is a response. A response has no conclusion and is
not evaluated against one, so evaluation and the validity check refuse
it with ARGUMENT_IS_RESPONSE. Absent means a standard argument.
Returns the conclusion PremiseEngine, or undefined.
Look up a variable by ID.
Returns all premises.
Returns supporting premises (inference premises minus conclusion).
Pre-evaluation structural validation.
Read-only interface providing the data an evaluation needs from an argument engine. This is intentionally narrow — evaluation should not mutate anything.