GALEN Reverse Compiler — Canonical Expansion

Revised GALEN Grammar

Fixed positional grammar specification

Every valid GALEN statement follows exactly one positional grammar. Position carries meaning. Deviation is a syntax error.

Full form

INTENT.DOMAIN: SUBJECT @RECIPIENT angle= tone= +/- context= >FORMAT

INTENT

Mandatory. Single uppercase letter. Defines the action to perform. G = Generate, Q = Query, E = Explain, S = Summarise, D = Data, C = Command, R = Revise

DOMAIN

Optional. Dot-separated after intent. Narrows the action type. G.email, G.report, Q.med, C.workflow

SUBJECT

Mandatory. Core topic or object. Compound subjects joined with dots. bariatric.surgery, overdue.invoices, customer.complaints

@RECIPIENT

Optional. Target recipient or system. Always prefixed with @. Position: first modifier. @finance, @gp, @customers

angle=

Optional. Purpose or framing of the output. Position: second modifier. angle=compliance, angle=risks, angle=benefits

tone=

Optional. Tone of the output. Position: third modifier. tone=formal, tone=plain, tone=urgent

+/- modifiers

Optional. Add (+) or reduce (-) scope. Position: fourth. +detail, -length, +comparison

context=

Optional. Jurisdiction, geography, system context. Position: fifth. country=UK, lang=en, system=crm

>FORMAT

Optional. Output format. Always last. >txt, >list, >brief, >full, >step, >json, >tbl

Canonical Token Dictionary

One token. One meaning. Always.

Every token maps to exactly one canonical English phrase. This is the complete dictionary. No token may appear outside this list without registering a new canonical definition.

Token	Canonical English expansion	Position
Intent tokens
G	Write	Intent (mandatory)
G.email	Write an email	Intent.Domain
G.report	Write a report	Intent.Domain
G.letter	Write a letter	Intent.Domain
G.summary	Write a summary	Intent.Domain
G.workflow	Execute the workflow for	Intent.Domain
G.plan	Create a plan for	Intent.Domain
Q	Provide information about	Intent (mandatory)
Q.med	Provide medical information about	Intent.Domain
Q.fin	Provide financial information about	Intent.Domain
Q.leg	Provide legal information about	Intent.Domain
Q.tech	Provide technical information about	Intent.Domain
E	Explain	Intent (mandatory)
S	Summarise	Intent (mandatory)
D	Record structured data for	Intent (mandatory)
D.med	Record structured clinical data for	Intent.Domain
C	Execute	Intent (mandatory)
C.travel	Create a travel itinerary for	Intent.Domain
R	Revise	Intent (mandatory)
Recipient tokens (@)
@finance	to the finance department	First modifier
@gp	to the general practitioner	First modifier
@surgeon	to the surgeon	First modifier
@cardiologist	to the cardiologist	First modifier
@customers	to all customers	First modifier
@management	to the management team	First modifier
@client	to the client	First modifier
@team	to the team	First modifier
Angle tokens (angle=)
angle=compliance	focused on compliance	Second modifier
angle=risks	focused on risks	Second modifier
angle=benefits	focused on benefits	Second modifier
angle=comparison	as a comparative analysis	Second modifier
angle=summary	as a high-level overview	Second modifier
angle=outcomes	focused on outcomes	Second modifier
Tone tokens (tone=)
tone=formal	in a formal tone	Third modifier
tone=plain	in plain language	Third modifier
tone=urgent	with urgency	Third modifier
tone=professional	in a professional tone	Third modifier
tone=empathetic	in an empathetic tone	Third modifier
Scope tokens (+/-)
+detail	with full detail	Fourth modifier
-length	brief	Fourth modifier
+comparison	including a comparison	Fourth modifier
+crm	and create a reminder in the CRM	Fourth modifier
+notify.finance	and notify the finance team	Fourth modifier
+top3	highlighting the top three items	Fourth modifier
+management.summary	with a management summary	Fourth modifier
+next	planned for the next step	Fourth modifier
+past	previously completed	Fourth modifier
Context tokens (context=)
country=UK	in the United Kingdom	Fifth modifier
country=US	in the United States	Fifth modifier
lang=en	in English	Fifth modifier
system=crm	within the CRM system	Fifth modifier
budget=low	on a budget	Fifth modifier
duration=3d	over three days	Fifth modifier
Format tokens (>)
>txt	as plain text	Last (mandatory position)
>list	as a list	Last
>brief	as a brief summary	Last
>full	in full detail	Last
>step	as step-by-step instructions	Last
>json	as structured JSON data	Last
>tbl	as a table	Last

Reverse Compilation Rules

GALEN → Canonical English

The reverse compiler follows a strict assembly order. Each position in the GALEN statement maps to a fixed position in the canonical English sentence.

Rule 1

Begin with the INTENT expansion. If -length is present, prepend "Write a brief" instead of "Write a". Apply -length before all other modifiers.

Rule 2

Expand SUBJECT by replacing dots with spaces. overdue.invoice.followup → "overdue invoice follow-up"

Rule 3

Append @RECIPIENT expansion immediately after subject. @finance → "to the finance department"

Rule 4

Append angle= expansion. angle=compliance → "focused on compliance"

Rule 5

Append tone= expansion. tone=formal → "in a formal tone"

Rule 6

Append all + modifiers in order of appearance. Join with commas if multiple.

Rule 7

Append context= expansions. country=UK → "in the United Kingdom"

Rule 8

Append >FORMAT expansion last, preceded by a comma. >txt → ", as plain text"

Rule 9

Capitalise the first character of the canonical output. End with a full stop.

Rule 10

Unknown tokens: expand by replacing dots with spaces and inserting into the sentence at the correct positional slot. Never discard a token silently.

Example 1

G.email: finance @finance angle=compliance tone=formal -length >txt

↓ canonical expansion

Write a brief formal email to the finance department focused on compliance, as plain text.

Example 2

Q.med: bariatric.surgery vs GLP1 +comparison country=UK >list

↓ canonical expansion

Provide medical information about bariatric surgery versus GLP1 including a comparison in the United Kingdom, as a list.

Example 3

G.workflow: overdue.invoice.followup @customers +crm +notify.finance angle=compliance >step

↓ canonical expansion

Execute the workflow for overdue invoice follow-up to all customers and create a reminder in the CRM and notify the finance team focused on compliance, as step-by-step instructions.

Example 4

C.travel: itinerary Tokyo budget=low duration=3d >list

↓ canonical expansion

Create a travel itinerary for itinerary Tokyo on a budget over three days, as a list.

Implementation

Pseudocode: GALEN → English compiler

// GALEN Reverse Compiler — Pseudocode
// Input: GALEN string · Output: canonical English sentence

function expandGALEN(galenString):

  // Step 1 — Tokenise
  parts = parse(galenString)
  // parts = { intent, domain, subject, tokens[] }

  // Step 2 — Detect -length early (modifies intent phrase)
  isBreif = parts.tokens.includes("-length")

  // Step 3 — Expand INTENT
  intentKey = parts.domain ? parts.intent + "." + parts.domain : parts.intent
  intentPhrase = DICTIONARY[intentKey] ?? "Perform action"
  if isBrief: intentPhrase = intentPhrase.replace("Write", "Write a brief")

  // Step 4 — Expand SUBJECT
  subjectPhrase = parts.subject
    .replace(/\./g, " ")
    .replace(" vs ", " versus ")

  // Step 5 — Assemble in canonical order
  sentence = [intentPhrase, subjectPhrase]

  // @recipient — first
  recipient = parts.tokens.find(t => t.startsWith("@"))
  if recipient: sentence.push(DICTIONARY[recipient])

  // angle= — second
  angle = parts.tokens.find(t => t.startsWith("angle="))
  if angle: sentence.push(DICTIONARY[angle])

  // tone= — third
  tone = parts.tokens.find(t => t.startsWith("tone="))
  if tone: sentence.push(DICTIONARY[tone])

  // + modifiers — fourth (in order, skip -length)
  plusTokens = parts.tokens.filter(t => t.startsWith("+"))
  plusTokens.forEach(t => sentence.push(DICTIONARY[t] ?? t.replace("+","")))

  // context= — fifth
  contextTokens = parts.tokens.filter(t => t.includes("=") && !t.startsWith("angle") && !t.startsWith("tone"))
  contextTokens.forEach(t => sentence.push(DICTIONARY[t] ?? t))

  // >format — last
  format = parts.tokens.find(t => t.startsWith(">"))
  if format: sentence.push(",", DICTIONARY[format])

  // Step 6 — Join and capitalise
  result = sentence.join(" ").trim()
  result = result[0].toUpperCase() + result.slice(1) + "."

  return result

Live Tool

Try the reverse compiler

Type any valid GALEN statement. It expands to canonical English in real time.

GALEN → English · Live Compiler ● Deterministic

Canonical English expansion will appear here...

Quick examples

G.email compliance

Q.med comparison

G.workflow invoice

C.travel Tokyo

S: complaints