In our dictionaries there are no special attributes for prepositions at the morphological level. At the configurational level, a semantic typing of prepositions helps to control attachment of modifiers:
ptype: norm, loc, orig, dest, nil.
In Spanish, some contractions of articles and prepositions can be found:
`a' + `el' = `al' `de' + `el' = `del'
For analysis purposes, these contractions are treated at the morphological level in EUROTRA-ES grammars as samples of a special category portmanteau and are decomposed before reaching the configurational level (ECS).