What does the symbol $\triangleright$ mean programming language semantics?  I've seen it in the context of datatypes in and the evaluation of expressions in environments.For example :$$tenv \triangleright erht \implies tval $$or$$tenv[tval/x]\triangleright ebody\implies t\,.$$Here, $tenv$ is an environment and $ebody$ is the body of some expression.
Meaning of $\triangleright$ in programming language semantics
terminology;logic;semantics
Most probably, in your context,  is just a syntactic separator, meaning in the environment to the left of , the formula to the right of  holds.However,  has no fixed meaning in general. I used it myself with completely different definitions.