Function hasDef

src/compute-engine/assume.ts:1163–1165

(ce: ComputeEngine, s: string)

      if (refineSymbolType(ce, symbol, 'real', cause) === 'contradiction')
        return 'contradiction';
    }
    // ...fall through to store the membership fact
  }

  // 6. Inert/unknown set: store a membership fact (design §4.1 — this used
  //    to throw "Invalid domain")