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ack

This folder contains an implementation of the Ackermann function (general recursive function). For a description of this function see e.g.

https://en.wikipedia.org/wiki/Ackermann_function

Print Logtalk, Prolog backend, and kernel versions (if running as a notebook):

%versions

Start by loading the example:

logtalk_load(ack(loader)).

Sample queries:

ack::ack(2, 4, V).

<!-- V = 11. -->

ack::ack(3, 3, V).

<!-- V = 61. -->

ack::ack(3, 4, V).

<!-- V = 125. -->

Sample queries for backends implementing the time/1 predicate. E.g., SWI-Prolog, Trealla Prolog, XVM, or YAP. The adapter files for SWI-Prolog and YAP ensure that a (::)/2 goal in the argument of the time/1 meta-predicate is compiled prior to calling it:

% auto-load the predicate in the case of SWI-Prolog
time(true).

<!-- true. -->

time(ack::ack(2, 4, V)).

<!-- % 98 inferences, 0.00 CPU in 0.00 seconds (0% CPU, Infinite Lips) V = 11. -->

time(ack::ack(3, 3, V)).

<!-- % 2,451 inferences, 0.00 CPU in 0.00 seconds (0% CPU, Infinite Lips) V = 61. -->

time(ack::ack(3, 4, V)).

<!-- % 10,326 inferences, 0.00 CPU in 0.00 seconds (0% CPU, Infinite Lips) V = 125. -->