^- [@ @] [3 4]
types combine from parts: [@ @] is the type of a cell of two atoms.
glossary
^- casts a value to a named type: it checks the value fits and relabels it.
^-(@ 42) is 42.
irregular forms:
a leading backtick cast - the type in backticks, then the value - is ^-
$: makes a tuple mold, naming each face in a cell.
$:(x=@ y=@) is the mold [x=@ y=@].
:* makes a tuple of many elements, nesting to the right.
:*(1 2 3) is [1 2 3].
irregular forms:
[a b c d] is :*(a b c d)