delete a confusing exercise from lesson 11 of the tutorial
@@ -120,16 +120,6 @@ As a result, if we were to write in the above grammar the term
should be chosen, whereas if we want the first derivation, we could write
`(I1:Int + I2:Int)::Exp`.
-#### Exercise
-
-Write a function `eval` which takes a term of sort `Exp2` and returns an `Int`.
-The function should be capable of evaluating any term of sort `Exp2` to the
-integer value which it expresses. You will need to write strict casts in order
-to disambiguate these rules. You will not be able to directly write terms of
-sort `Exp2` directly in a program, so you will have to create new function
-symbols that rewrite constant symbols to terms of sort `Exp2` and use strict
-casts to disambiguate their right-hand side.
-
### Projection casts
Thus far we have focused entirely on casts which exist solely to inform the
