Tcl contains some semantic equivalences such as:

'''$ ~~ [[[set]]]'''

'''[[]] ~~ [[[eval]]]'''

'''"" ~~ [[[subst]]]'''

Where ''~~'' can be read as ''is semantically equivalent to''

Add more if you find them.  The hunt is on.
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''[escargo] 7/7/7 -'' Are you looking for examples how these are '''not''' equivalent?

For example, I seem to recall that [[[eval]]] does a round of substitution before evaluating
its input.  (Logically, it would seem to be necessary for '''[[]] !~ [[[eval]]]''', otherwise
eval is just taking up space.)

And [subst] takes arguments that allow limitations on the substitutions.

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[Category Language]