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prolog

how to enter a range of numbers in prolog?

I'm trying to input a table and need to put the range of the age in the library. How can I do it in Prolog?enter image description here

  `patients(Z,20,5,0):-Z#<19,Z#>0.
  patients(Z,39,6,2):-Z#<39,Z#>20.`
Solution

  • It completely depends on what you want to do. The above are just facts, so you can represent them as Prolog facts, i.e. clauses without a body.

    Filling in the facts for the relation (which may be called patient_stats) is exactly like entering a relation into an RDBMS:

    % patient_stats(AgeGroupId, NumOfCases, NumOfHospitalizations, NumOfDeaths)

patient_stats(age_group_a,20,5,0).
patient_stats(age_group_b,39,6,2).
% etc..

% age_group(LowestIncl,HighestIncl)

age_group(age_group_a,0,19).
age_group(age_group_b,20,39).
% etc...

    Now you can perform joins, use library(aggregate), the usual fun.

    For example, with the above facts, we can get a list of tagged values:

    join_patient_stats_x_age_group(Found) :-
   findall([low_age(LowestInct),
            high_age(HighestIncl),
            num_cases(NumOfCases)],
       (age_group(G,LowestInct,HighestIncl),
        patient_stats(G, NumOfCases, _,_)),
       Found).

    Then:

    ?- join_patient_stats_x_age_group(F).
F = [[low_age(0), high_age(19), num_cases(20)],
     [low_age(20), high_age(39), num_cases(39)]].