What does '...' notation mean in Blind Signatures For Untraceable Payments of David Chaum
On the page 4 of Blind Signatures For Untraceable Payments it is written:
Conservation of signatures--provider can create at most one stripped signature for each thing signed by signer (i.e. even with s'(c(x1)) ... s'(c(xn)) and choice of c, c', and xi, it is impractical to produce s'(y) such that r(y) and y≠xi).
I get it from the context that the passage is about the impracticality of producing
two private keys of the same value within a reasonable amount of time.
But I want to be sure that I understand Chaum correctly, hence I would
like to know what ... means in his formula.
Is ... equivalent to some other more commonly used notation?