I am reading the paper "Entropy and Equilibrium States in Classical Statistical Mechanics" by Oscar E. Lanford III (published in 1973). The image below shows an excerpt where the symbol $\lor$ is used in a way that I don't understand (in the equation boxed in red). This is the first instance of the $\lor$ symbol in the paper, and there is no definition of the symbol.
For reference, $V(\Lambda,N,J)$ is a real valued function where $\Lambda$ is a subset of $R^N$, $N$ is a positive integer, and $J$ is a subset of $R$.
What might the $\lor$ symbol mean here?
