feat: add Catalan number substInv eval problem - #3
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Uses the newly formalized compositional inverse (substInv) to state that the coefficients of substInv(X - X²) are the Catalan numbers. Classical application of Lagrange inversion in enumerative combinatorics. Bumps mathlib to include the power series substInv PR. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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This was referenced Aug 22, 2026
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Summary
substInv(X - X^2)are the Catalan numbersC_n = (2n choose n)/(n+1)50d5513e83cto include the power seriessubstInvAPITest plan
lake build FormalMathEval.Combinatorics.CatalanSubstInvcompiles (sorry is expected)lake exe eval_inventorylists the new problem🤖 Prepared with Claude Code