An after lammā in the quoted construction is additional in this grammar. An plus a subjunctive imperfect in an infinitival construction is governing. Use context, not shape.
Opening interactive controls...
Decision Rule for An
Additional Particles: Seven Forms, Emphasis and Syntactic Case
An after lammā in the quoted construction is additional in this grammar. An plus a subjunctive imperfect in an infinitival construction is governing. Use context, not shape.