1. Exhaustive enumeration. Every binary tree with 0 through N internal eml nodes is generated exactly once. Leaves always evaluate to 1. The total is the sum of Catalan numbers C(0) + … + C(N).
2. Complex evaluation. Each tree is evaluated over ℂ using strict principal-branch ln: arg(z) ∈ (−π, π]. If ln(0) is reached at any intermediate node, the tree is skipped (counted as an error).
3. Distance to target. The result is compared to the target value by |z − target| in ℂ. A distance below 1×10⁻⁸ counts as a construction found.
4. Deterministic. Unlike gradient descent, this search is exhaustive: if no construction exists up to N nodes under this grammar, it will not be found. Sanity checks: e (1 node), 0 (3 nodes), −iπ (11 nodes).