[developers] portuguese hpsg

[Ann Copestake]

I guess in addition to Valia's references, I should have acknowledged:

Condoravdi C.
        March 1990, "Symmetric Predicates, Verbal Classes
        & Diathesis Alternations"
        ESPRIT BRA-3030 ACQUILEX WP NO.003

(I don't think I actually have a copy, though ...)

I believe there's also discussion about the symmetry or otherwise by Dowty in 
the context of the more general discussion of thematic roles.