 Very recently, Sergei Tupailo (2010) has proved the consistency of NFSI, the fragment of NF consisting of extensionality and those instances of Comprehension (\(\{x \in A \mid \phi \}\) exists) which are stratified and in which the variable \(x\) is assigned the lowest type. Tupailo’s proof is highly technical, but Marcel Crabbé pointed out that a structure for the language of set theory in which the sets are exactly the finite and cofinite collections satisfies this theory (so it is very weak). It should be noted that Tupailo’s model of NFSI satisfies additional propositions of interest not satisfied by the very simple model of Crabbé, such as the existence of each Frege natural number. It is of some interest whether this new fragment represents an independent way of getting a consistent fragment of NF. Note that NFU+NFSI is NF because NFSI has strong extensionality. Also, NFP+NFSI is NF because NFSI includes Union. The relationship of NFSI to NF\(_3\) has been clarified by Marcel Crabbé in 2016. Tupailo’s theory is shown not to be a fragment of Grishin’s, and thus represents a fourth known method of getting consistent fragments.