for Al being QC-alphabet
for p being Element of CQC-WFF Al
for x, y being bound_QC-variable of Al
for A being non empty set
for J being interpretation of Al,A
for v being Element of Valuations_in (Al,A) holds
( J,v |= p . (x,y) iff ex a being Element of A st
( v . y = a & J,v . (x | a) |= p ) )