The blocks that are not programs were the ones that had drifted: the usage text
had lost its indentation and the refusal table had trimmed "(see plan.org)" off
every message, so the page was showing wording the compiler does not print.
Everything here is checked against the compiler rather than against plan.org:
the design documents describe a language larger than the one that runs, and a
page that documented the plan would mislead the first person to try it.
