# Is there a reason $⊑$ in CSP is analogous to $⊇$ (as opposed to $⊆$)?

The 'square' subset symbols are sometimes used to express analogous concepts to subsets, like prefixes or suffixes.

However their use in CSP seems to be counterintuitive to their shape: $$⊑$$ appears analogous to $$⊇$$ (as opposed to the more similar looking $$⊆$$):

A process $$P$$ refines $$Q$$, denoted as $$Q⊑_TP$$, iff $$traces(P) ⊆ traces(Q)$$.

Does Hoare explain anywhere why he chose this orientation of the symbol?

• Maybe my browser isn't rendering well, but I don't see that symbol on the Wikipedia page. Did you quote from some other source? – Carl Witthoft Jan 30 at 12:52