Encoding An Assumption By Reference To An Attribution

A plausible assumption is that the principles of language are fixed and innate. (Chomsky 2000: 122; New Horizons)

A plausible assumption	is	the principles of language are fixed and innate
Value/Identified	Process	Token/Identifer
		the principles of language are fixed and innate Carrier Process Attribute

Note the use of double markedness as a device for 'manufacturing consent': the clause is both 'receptive', rather than 'operative', and 'encoding', rather than 'decoding'.  Note also the textual packaging of the plausibility of the assumption as Given:

A plausible assumption	is	the principles of language	are	fixed and innate
Theme	Rheme
Given				New

Of course, this is not a plausible assumption, because Chomsky also assumes that the principles of language are components of a "genetically-determined" language faculty, and as the evolution of biological species demonstrates, genes and their expressions are not "fixed".  If they are "innate", they are not "fixed".  Platonic essentialism/idealism is not empirical science.