Suppose you have a valid argument. Can you render the argument invalid by changing the display order of the premises?
I should think never. The Dark Ostrich, however, offers the following putative counterexample. He says he got it from Sainsbury; I should like to see a reference. And if there is a literature on this, I should like to see a bibliography.
(A) Some Greek is called ‘Mark’, Mark is an evangelist, therefore some Greek is an evangelist. (VALID)
(B) Mark is an evangelist, some Greek is called ‘Mark’, therefore some Greek is an evangelist. (NOT VALID)
(A) is valid and (B) is not. But this is not evidence that premise order affects validity. For while the sentences are the same, the premises of the two arguments are not the same. Made explicit, (A) becomes
(A*) Some Greek is called 'Mark', this same individual called 'Mark is an evangelist, therefore some Greek is an evangelist.
Clearly, (A*) and (B) have different premises. So it is not the different order of the premises in (B) that causes it to be invalid.