#import "@preview/prooftrees:0.1.0": * #let db(x) = $bracket.l.double #x bracket.r.double$ #let isValue(x) = $#x "value"$ #let mapsto = $arrow.r.long.bar$ #let mapstostar = $op(arrow.r.long.bar)^*$ #let subst(x, v, e) = $#e [#v\/#x]$ #let TODO = text(fill: red)[*TODO*] #let conf(title, doc) = { show link: underline set page(width: 6in, height: 9in, margin: 0.3in) text(size: 30pt)[#title] doc }