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javaartificial-intelligenceagent

How to get the value of a literal in Agentspeak

A have 3 working agents in written in agentspeak. Two of them have a belief +number(someNumber) and the third is trying to compute the minimum of these two. What I have now is the middle agent receiving both literals from the two agent, but as both are literals, normal math.min() operation cannot be used here:

+!test: iam(root) <-
    .send("agent14", askOne, number(RE), L);
    .send("agent15", askOne, number(RE2), R);
    .print("Both got numbers: ", L, " ", R);
    +number(math.min(L, R));
    .print("DONE").

here the math.min() function produces an error, as it is not implemented for the data type:

[ArithFunctionTerm] Error in 'math.min(L,R)' (agent.asl:36) -- error in evaluate!
jason.JasonException: math.min is not implemented for type 'number(65)[source(agent14)]'.

Is there a way to compare these two values?

Solution

  • The origin of the problem is the answer of askOne: a literal of the same type as the one used to ask. Thus L unifies with number(65) and R unifies with number(<somenumber>). Since they are literals (and not numbers), they can not be used by math.min.

    The solution is to exploit unification in the fourth arg of .send:

    .send("agent14", askOne, number(RE), number(L)); .send("agent15", askOne, number(RE2), number(R));

    now L and R are unified with numbers and math.min will work.