Reduction tree

All four reduction strategies advance in parallel. When two strategies produce different results, the tree branches. When they re-converge to an α-equivalent state, the branches merge back. Drag nodes around — the tree wobbles.

normal applicative cbn cbv · hover a strategy to highlight its path · drag · scroll to zoom

100%

Type an expression above and press Set.

Try: plus 2 3 · (\x. x x) (\x. x x) · fact 3 · pred 4

Keyboard shortcuts

Step / run

Space / →: Advance one β-step (all strategies in lockstep)
R: Toggle Run (auto-advance)
S: Set / reset the tree (re-parse the input expression)

View

F: Fit the whole tree to the viewport
M: Toggle the minimap
Mouse wheel: Zoom at cursor
Click + drag (canvas): Pan
Double-click (empty area): Reset viewport
Corner controls: −/+ zoom, ⊙ fit to view, ⛶ fullscreen

Nodes

Click + drag (node): Move node — drag glides through edges
Click (no drag): Open fullscreen for that node
Hover legend chip: Highlight that strategy's path

Fullscreen view

Esc: Close fullscreen overlay

This dialog

?: Open / close this list

Step —