---
title: "The Syntax and Semantics of the Proposed International Algebraic Language of the Zurich ACM-GAMM Conference"
authors:
  - "J. W. Backus"
year: 1959
venue: "ICIP Paris"
arxiv: null
doi: null
source: "https://www.softwarepreservation.org/projects/ALGOL/paper/Backus-Syntax_and_Semantics_of_Proposed_IAL.pdf"
topics:
  - bnf
  - algol
  - backus
  - metalanguage
seed_rank: 624
seed_batch: "foundations-greats-2026-08-13"
reviewed: "2026-08-13"
pool: "languages"
relevance_score: 9
lineage: foundations-of-computing
cites:
  - title: "The FORTRAN Automatic Coding System"
    url: "https://doi.org/10.1145/1455567.1455599"
    year: 1957
    arxiv: null
    doi: "10.1145/1455567.1455599"
  - title: "On Certain Formal Properties of Grammars"
    url: "https://doi.org/10.1016/S0019-9958(59)90362-6"
    year: 1959
    arxiv: null
    doi: "10.1016/S0019-9958(59)90362-6"
see:
  - "622-the-fortran-automatic-coding-system"
  - "601-on-certain-formal-properties-of-grammars"
---

# The Syntax and Semantics of the Proposed International Algebraic Language of the Zurich ACM-GAMM Conference

## One-sentence takeaway

Backus’s ICIP 1959 IAL paper introduces a metalinguistic formula notation — the immediate parent of BNF — so a language’s syntax can be written as a grammar.

## Why it matters here

Syntax-notation root before the Algol 60 report. Every ano/GRID COMMAND grammar file is this idea: a metalanguage whose sentences are productions, not English.

## Key ideas

- Metalinguistic formulas with `::=` / alternatives describe the proposed Zurich IAL (Algol 58).
- The metalanguage is itself a formal grammar, so syntax is no longer an informal appendix.
- Semantics are still sketched in prose; the lasting contribution is the syntax notation Naur will polish into BNF.
- Software Preservation Society hosts the canonical scan of the Paris ICIP paper.

## Caveats

## Links

- Scan: https://www.softwarepreservation.org/projects/ALGOL/paper/Backus-Syntax_and_Semantics_of_Proposed_IAL.pdf