Abstract
As a generalization of Rota–Baxter algebras, the concept of an -Rota–Baxter could also be regarded as an algebraic abstraction of the integral analysis. In this paper, we introduce the concept of an -dendriform algebra and show the relationship between -Rota–Baxter algebras and -dendriform algebras. Then, we provide a multiplication recursion definition of typed, angularly decorated rooted trees. Finally, we construct the free -Rota–Baxter algebra by typed, angularly decorated rooted trees.