SENTENCE in List Utilities lib doesn't work

... when given a sentence:

The problem is in the compiled MAP:

Good catch, thanks!

@jens: I'll file a PR for the library, but does this count as a bug in compilation?

compiling custom blocks isn't supported anyway, so the bug would be not raising an error message. But, seriously, JIT compilation is still very much experimental and not a general-purpose feature, plus it has been sorta superseded by hyperblocks and my making plain MAP fast enough for just about anything.