sin and cos in the prelude rather than copied per file, with the caveat
sqrt does not have: IEEE-754 makes sqrt correctly rounded and requires
nothing of the kind for sine, so these are the one place the prelude may
disagree bit for bit between native and wasm32. A program hashing output
across targets must not route the hash through one.
Arithmetic folds left over as many operands as you write, and so does the
constant folder, which otherwise refused (defconst n (* 2 3 4)) after the
checker had accepted it. One operand is refused by name: there is no unary
minus, and the message points at (- 0 x), which is what the prelude writes.
The typed let binding is a grammar question and is written up rather than
guessed at. The break banner premise had gone stale -- check.sh already
runs that demo under a timeout and keeps what it printed.
Joseph Ferano
d803078699