Garbage collector of unused bindings in the evaluator #36
Description
Currently the evaluator can accumulate a large number of value bindings in its environment that are not used anymore in the focus term or the continuation stack. It could be worth it to speed up evaluation by doing some kind of garbage collection on this environment.
If we had this kind of garbage collection, then we could also consider changing the strategy we use for turning a state of the AM back into a regular term: instead of substituting away the bindings, we could turn them into let-bindings. (Without garbage collection, this would result in a huge number of unused let-bindings.)