Original sentence: Both sets of axioms have four existential quantifiers.No axiom requires more than three quantified variables.Point-free geometry was first formulated in Whitehead (1919, 1920),  not as a theory of geometry or of spacetime, but of "events" and of an "extension relation" between events.The two formal first order theories described in this entry were devised by others in order to clarify and refine our understanding of Whitehead's theories
Edited sentence: Each set of axioms has but four existential quantifiers.No axiom requires more than three quantified variables; hence a translation of first order theories into relation algebra is possible.Point-free geometry was first formulated in Whitehead (1919, 1920), not as a theory of geometry or of spacetime, but of "events" and of an "extension relation" between events.The two formal first order theories described in this entry were devised by others in order to clarify and refine Whitehead's theories