turnstiles

noun

1. 1

   A rotating mechanical device that controls and counts passage between public areas, especially one that only allows passage after a charge has been paid.

2. 2

   A similar device in a footpath to allow people through one at a time while preventing the passage of cattle.

3. 3

   The \vdash symbol used to represent logical entailment (deducibility relation), especially of the syntactic type; i.e., syntactic consequence. (Such symbol can be read as "prove(s)" or "give(s)". )