1. A method for parallel execution of specified operations upon data having a hierarchical syntactic structure, said structure comprising expressions nested within expressions, said specified operations to be executed on specified ones of said expressions, comprising the steps of: 1. Entering said data into an assemblage of cells, each cell comprising computational resources and communications resources, 2. Forming a processing network by apportioning said computational resources to form, in said cells, nodes in correspondence with certain expressions of said data, and apportioning said communications resources to form channels connecting said nodes, said processing network comprising said nodes interconnected by said channels, said processing network having a hierarchical structure corresponding essentially to said hierarchical syntactic structure of said data, each said node comprising computational resources entirely within one of said cells and each said channel comprising communications resources within at least one of said cells, and connecting two said nodes, at least one of which comprises computational resources belonging to the same cell as do certain communications resources forming said channel, and 3. Executing said operations upon said data by using said apportioned computational resources of said nodes to execute said operations on said expressions in respective correspondence with said nodes, and using said channels for communications among nodes coupled by said channels during said execution.