# Top-down and Bottom-up Evaluation Procedurally Integrated

arXiv: https://arxiv.org/abs/1804.08443 · HTML: https://mlsanity.com/paper/1804.08443/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 23 Apr 2018.

## Built on by (most cited first, 1 of 1)

- [The Horn Non-Clausal Class and its Polynomiality](https://mlsanity.com/paper/2108.13744/) (2021)

## Abstract (arXiv)

This paper describes how XSB combines top-down and bottom-up computation through the mechanisms of variant tabling and subsumptive tabling with abstraction, respectively. It is well known that top-down evaluation of logical rules in Prolog has a procedural interpretation as recursive procedure invocation (Kowalski 1986). Tabling adds the intuition of short-circuiting redundant computations (Warren 1992) .This paper shows how to introduce into tabled logic program evaluation a bottom-up component, whose procedural intuition is the initialization of a data structure, in which a relation is initially computed and filled, on first demand, and then used throughout the remainder of a larger computation for efficient lookup. This allows many Prolog programs to be expressed fully declaratively, programs which formerly required procedural features, such as assert, to be made efficient. This paper is under consideration for acceptance in "Theory and Practice of Logic Programming (TPLP)".