Why Sigil Uses true and false

Sigil originally used ⊤ and ⊥ for booleans. The language now uses true and false instead.

Why the Change Happened

The symbolic literals were visually distinctive, but they were a poor fit for Sigil's actual goals. They cost more under the tokenizers that matter for the repo, they are less likely to be produced naturally by coding agents, and they increase the chance of simple parse failures in ordinary editing environments.

None of those costs were offset by a real language-design benefit.

Why ASCII Won

true and false have three advantages:

• they are cheaper or comparable under real tokenization
• they align with the priors of existing coding tools and agents
• they remain explicit and easy to read

The important point is not that symbolic booleans are inherently bad. It is that Sigil wants canonical syntax that works well in the environments where the language is actually being written and generated.

Result

Booleans now follow the same general policy as the rest of Sigil's recent syntax changes: when a mathematically elegant spelling loses on machine-facing ergonomics and token cost, the language prefers the more practical canonical form.