▁For ▁example , ▁if ▁P ( x ) ▁is ▁the ▁propos itional ▁function ▁" x ▁is ▁married ", ▁then , ▁for ▁a ▁universe ▁of ▁disc ourse ▁X ▁of ▁all ▁living ▁human ▁be ings , ▁the ▁universal ▁quant ification ▁Given ▁any ▁living ▁person ▁x , ▁that ▁person ▁is ▁married ▁is ▁given : ▁ ▁It ▁can ▁be ▁seen ▁that ▁this ▁is ▁ir rev oc ably ▁false . ▁Tr uth fully , ▁it ▁is ▁stated ▁that ▁It ▁is ▁not ▁the ▁case ▁that , ▁given ▁any ▁living ▁person ▁x , ▁that ▁person ▁is ▁married ▁or , ▁symbol ically : ▁. ▁ ▁If ▁the ▁statement ▁is ▁not ▁true ▁for ▁every ▁element ▁of ▁the ▁Un iverse ▁of ▁Disc ourse , ▁then , ▁pres uming ▁the ▁universe ▁of ▁disc ourse ▁is ▁non - empty , ▁there ▁must ▁be ▁at ▁least ▁one ▁element ▁for ▁which ▁the ▁statement ▁is ▁false . ▁That ▁is , ▁the ▁neg ation ▁of ▁ ▁is ▁log ically ▁equivalent ▁to ▁" There ▁exists ▁a ▁living ▁person ▁x ▁who ▁is ▁not ▁married ", ▁or : ▁ ▁Gener ally , ▁then , ▁the ▁neg ation ▁of ▁a ▁propos itional ▁function ' s ▁universal ▁quant ification ▁is ▁an ▁exist ential ▁quant ification ▁of ▁that ▁propos itional ▁function ' s ▁neg ation ; ▁symbol ically , ▁ ▁It ▁is ▁err one ous ▁to ▁state ▁" all ▁persons ▁are ▁not ▁married " ▁( i . e . ▁" there ▁exists ▁no ▁person ▁who ▁is ▁married ") ▁when ▁it ▁is ▁meant ▁that ▁" not ▁all ▁persons ▁are ▁married " ▁( i . e .