13.5.1 "[[Call]]" / step 3
14 "Program" / Runtime Semantics: Program Evaluation / step 3
15.1.2.1 "eval (x)" / step 3
Each of these uses the instruction
"Establish and enter a new execution context"
I believe that in 13.5.1, this is supposed to define the variable 'calleeContext', and in 14, the variable 'progCxt', which are not explicitly defined.
So, to make things explicit, it would be better to use phrasing like:
"Let calleeContext be a new execution context."
15.1.2.1 doesn't use a variable to refer to the new execution context, but maybe it would be better if it did. (Certainly, it would be more consistent with 13.5.1 and 14.)
Sorry, my mistake. I was looking at the wrong thing.