Replace this with an equivalent program.
Replace this with an equivalent program.

The new program cases on a pair instead of inlining `fst' and `snd' everywhere.

The test still fails due to parsing of literals. It is impossible to write the
currently returned result in concrete syntax, because `-1/2` is parsed as
`int2real(-1) * prob2real(recip(nat2prob(2)))'.

zachsully/hakaru,zachsully/hakaru