%% %CopyrightBegin%
%%
%% SPDX-License-Identifier: Apache-2.0
%%
%% Copyright Ericsson AB 2021-2025. All Rights Reserved.
%%
%% %CopyrightEnd%

[;1m  is_a_function(BinRel)[0m

  Returns [;;4mtrue[0m if the binary relation [;;4mBinRel[0m is a function or
  the untyped empty set; otherwise, returns [;;4mfalse[0m.

[;1mExamples[0m

    1> sofs:is_a_function(sofs:relation([{1,a},{2,b},{3,c}])).
    true
    2> sofs:is_a_function(sofs:relation([{1,a},{1,b},{3,c}])).
    false
    3> sofs:is_a_function(sofs:set([a,b,c])).
    ** exception error: bad argument
         in function  sofs:is_a_function/1
