hubieran comprobado
-they/you had checked
Past perfect subjunctiveellos/ellas/ustedesconjugation ofcomprobar.

comprobar

Y si hubieran comprobado sus propuestas una a una, tampoco habrían anunciado ustedes la retirada de propuestas que ya habían sido retiradas, pues seguramente se habrían percatado del error.
If you had checked them one by one, you would not have announced the withdrawal of proposals that had already been withdrawn, for it is to be presumed that you would have noticed the mistake.
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