eval raises this exception when it fails to reduce/evaluate
a term, because it has components for which no
reduction/evaluation is defined, such as `x y`. The
- reduction-based interpreter just signals this with a normal
+ substitute-and-repeat interpreter just signals this with a normal
return value; but the environment-based interpreter uses an
exception to abort prematurely.
eval raises this exception when it fails to reduce/evaluate
a term, because it has components for which no
reduction/evaluation is defined, such as `x y`. The
- reduction-based interpreter just signals this with a normal
+ substitute-and-repeat interpreter just signals this with a normal
return value; but the environment-based interpreter uses an
exception to abort prematurely.