use strict;
use warnings;
use Data::Dumper;

my @AoA = (['a','b','c'],
           ['a','b','c'],
           ['a','b','d'],
           ['a','b','d']);

my %temp=();
my @aoa=map{[split $;,$_]}grep{++$temp{$_}<2} map {join $;,@$_} @AoA;
print Dumper \@aoa;
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