Complex sentence: The Herbrand theory establishes a link between quantification theory and sentential logic which is important in that it gives a method to test a formula in quantification theory by successively testing formulae for sentential validity.
Split into simpler sentences: The Herbrand theory establishes a link between quantification theory and sentential logic. This link is important because it gives a method to test a formula in quantification theory by successively testing formulae for sentential validity.