PROESA is incorrectly written, and should be written as "feat" being its meaning: See: feat.
I presume that by a spelling mistake yours, you are referring to EXPLOIT, that is a feat or extraordinary achievement obtained in performing a difficult or complicated task for ordinary people. It is my deduction, although I may be wrong.
PROESA is incorrectly written, and should be written as "feat" being its meaning: Feat: f. feat, courage or action courageous, heroic action.