They mean extrinsically, rather than intrinsically. Their properties are essentially nothing alike. P-langs not having a semantics in anything other than a met

They mean extrinsically, rather than intrinsically. Their properties are essentially nothing alike. P-langs not having a semantics in anything other than a metaphorical sense. Their extrinsic properties are similar insofar as they are inventions of human beings which have some socio-cultural dimension.