Command line

delhi check <FILE>                          parse, ground, and validate
delhi state <FILE> [-a ACTION]…             facts, and each agent's attitudes
delhi show  <FILE>                          the model itself, in explicit form
delhi eval  <FILE> [-a ACTION]… -f φ        evaluate one formula
delhi ask   <FILE> [-a ACTION]… -q π        enumerate what holds; `_` is the hole
delhi step  <FILE> -a <ACTION>…             apply actions in sequence
delhi dot   <FILE>                          Graphviz
delhi repl  <FILE>                          explore interactively
delhi gui   [DIR] [-p PORT]                 browser UI over a folder of .delhi files
delhi bench <FILE> [-n CYCLES] -a ACTION…   model growth and timing
delhi --version | --help

Flags

  • -a ACTION… — apply a trace before answering. Takes any number of ground action names. Available on state, eval, ask, step and bench.
  • -f FORMULA — the formula for eval.
  • -q PATTERN — the pattern for ask; _ marks the hole.
  • -d DEPTH — modal nesting depth for ask candidates. Default 0.
  • --json — one JSON object on stdout, errors included. On check, state, eval and ask.

Exit codes
0success, or the formula holds
1the file was rejected, or the formula does not hold
2usage error, a malformed formula, or an unknown action

The 1 / 2 split is deliberate: 2 means the question was wrong, 1 means the answer was no. A script that conflates them turns a typo into a refutation.

Colour

On when stdout is a terminal, off otherwise — so delhi dot … | dot -Tpng stays byte-clean. NO_COLOR=1 forces it off, CLICOLOR_FORCE=1 forces it on through a pipe.

The REPL

$ delhi repl examples/coin_lie.delhi
> B[carol] h              a bare formula evaluates
> :do peek_c()            apply an action
> :undo                   drop the last
> :reset                  clear the trace
> :state                  the state view
> :ask B[alice] _         enumerate; `:ask 2 …` sets the depth
> :actions                what can be applied
> :help

The browser UI

delhi gui serves the current directory — your own folder of .delhi files, not the repository. The ten examples are compiled into the binary, so a fresh install still opens on something readable.

cd ~/my-domains && delhi gui        # or: delhi gui ~/my-domains -p 9000

Editor with syntax highlighting and clickable errors, an actions rail, a live state view, a model graph, and a console with command history. Every divider is draggable. It binds to loopback and has no authentication, because it is a debugging tool for the machine it runs on — do not expose it.