derives

hypermath | formal-universality | dictionary

What it is

derives is the directional approach relation: derives(x, y) :: Prop asserts that from x, y is reachable by □-application. Semantically: there exists a finite chain of □-applications from x that produces a form `=~` to y.

derives :: Form -> Form -> Prop
-- Closed in L1 Section IV:
-- derives(x, y) := exists-n :: Ordinal, apply^n(x) =~ y

What it is not

What it clarifies

Grounds the deriver's purpose: the deriver is the form that traverses the derives relation — it follows the directed paths in the derivation matrix D.

Clarifies the FRAME status in L0: derives-is-directional was a FRAME in L0's self-kernel because the full proof of asymmetry required L1's relation language (the distinction between `~~` and `=~` levels). It is now FORM, discharged in L1 Section V.

Concrete example

derives(ground, apply(ground))    -- FORM. One application, direction established.
-- Not: derives(apply(ground), ground) at =~ level
--   (the ~~ orbit return does not satisfy the =~ landing requirement)

Visualization

A river that flows one way. You can trace upstream (find earlier derivations) but you cannot reverse the flow by assertion. The direction is set by the generative sequence. derives names that directional flow.

Speculation

Whether the derivation matrix D encodes derives directly — whether D[x][y] being defined is equivalent to derives(x, y) — is an OPEN bridge to formalize. If that bridge closes, derives becomes the computational API of D, composing with discharge to make automated derivation verification a matrix lookup. Combined with graduation, automated derives-checking would make layer boundaries self-policing.