Supérieur à, inférieur à, intérieur à, extérieur à (irregular comparatives)

Look at this comparison:

Note that some adjectives are naturally comparative and have no comparative or superlative form, and they use à rather than que:

supérieur/e à (superior to)

inférieur/e à (inferior to)

These less used adjectives also lack superlatives and comparative forms:

intérieur à (interior to)

extérieur à (exterior to)

Note that the preposition à will become au or aux when followed by articles le or les.
See À + le = au, à + les = aux, de + le = du, de + les = des (contractions of articles)