LDL++ Demo Programs

A sample of LDL++ programs grouped by their most significant traits:

Processing recursive structures: appending, merging, and sorting lists, Fibonacci, Ackerman, Hanoi and other Prolog favorites: programs.
Relations by blood, marriage, by transitive closure and beyond (same-generation, and blue-bloded Frenchmen): programs, facts..
BOM examples. Materials program, and facts, and the bike program and facts.

A travel-agent program on an internal database: program, and facts.
The same rules on external databases: program (including Sybase, Ingres, and those satisfying interchange standards such as RDA, SQLink, and ESS)
Other connections to outside databases: family relations stored in Sybase family.syb
Offloading aggregates to external SQL DBs: query forms, rules, and
schemas for DB2, Sybase, and Oracle.

The program all_letters.prg applied to all_letters.fac finds all the words that are closely related by calling the function all_letters.cc
The program airline.prg makes reservations from airline.fac, calling airline.cc
There is also a: makefile

Metafamily relations: meta_family.prg

The program agg_ex1.prg returns averages every 5 records. Test it on the data agg_ex1.fac you will get the result agg_ex1.out
The program agg_ex2.prg returns sum value until it exceed 100. Test it on the data agg_ex2.fac you will get the result agg_ex2.out
On-line Average Estimation: this program agg_ex3.prg returns an estimated average of the underlying database: agg_ex3.fac. The program will stop if the estimated value is within a close interval to the exact average. The result agg_ex3.out
On-line Median Estimation: this program agg_ex4.prg returns an estimated median value of the underlying database: agg_ex4.fac. The program will construct a tree to compute medians, and the estimated median is on the top of the tree. See the result agg_ex4.out
Temporal Projection: this program agg_tmp_proj.prg will coalesce the time-iterval in the relation when applied to test data agg_tmp_proj.fac and give out the following result agg_tmp_proj.out.
Data Cube Aggregates: The program agg_cube.prg demonstrates how to aggregate data on serveral dimesnions simultaneously. Given the sales data sorted on year, quarter, month, day ( agg_cube.fac) , the result agg_cube.out shows the aggregate sales for each time interal.

Join the Party Problem: We have a party where a person will come to the party if at least K friends will come. The program agg_mono1.prg defines a monotonic aggregate mcount. Given the extensional data (agg_mono1.fac), the result is agg_mono1.out.
Least-Distance Problem: Given a graph g(X,Y,C) (defined in agg_mono2.fac), where C is the cost of an edge from node X to node Y. The monotonic aggregates defined in agg_mono2.prg will find the least cost distance between any two nodes.
Company-Control Problem: owns(C1,C2,Per) denotes the percentage of shares of corporation C2 owned by corporation C1. Then C1 controls C2 if it owns more than, say 49% of its shares. The monotonic aggregates defined in agg_mono3.prg will decide the transitive ownership and control between corporations.
Bill-of-Materials (BoM) Problem: Monotonic aggregates are defined in agg_mono4.prg to solve BoM problems based on the facts provided in agg_mono4.fac.

Reachable Nodes:Program xy_reach.prg returns the nodes reachable from a given node and the distance. Test it on the data xy_reach.fac you will get the result xy_reach.out
Ancestor & Generation Gap: Quite similar to Reachable Nodes, program xy_ancestor.prg returns each ancestor of a given person and the generation gap between them. Test data: xy_ancestor.fac. Result: xy_ancestor.out
Floyd's Algorithm: Program xy_floyd.prg returns the Floyd's least cost path of a graph. Test it on the data xy_ex3.fac you will get the result xy_floyd.out
Bill of Material: For each part X, program xy_bom.prg counts its basic components Y. Test it on the data xy_bom.fac you will get the result xy_bom.out