Listing-level variables (chain + selection refs) feeding into variation pricing. No @price_* deps.

Listing vars referencing other listing vars; used in a variation price formula.

Uses @price_* dependencies AND listing vars; great for end-to-end pricing evaluation.

Listing variable references an undefined @name (neither a variation nor another listing var).

Listing variable references itself (@foo).

Cycle in listing variables: a → b → c → a.

Listing variable formulas may NOT reference @price_* variables.

Listing variable name collides with a variation variable name (disallowed by listing schema).

Listing variable names cannot start with "price_" (reserved).

Topological order + computed @price_* chaining (if DISABLE_PRICE_GRAPH is false).

Multiple dependents + mixed casing in @price_* references.

Variation references a non-existent @price_depth variable.

A variation references its own @price_* value.

Two-node cycle to verify cycle detection messaging.

Three-node cycle to validate cycle path reporting.