I suggest you read this post about why dynamically named variables are a bad idea. Instead, you'd be better off storing your vectors in cell arrays, as in my code below.
% Define the inputs
head = {[1 6], [7 9 13], [20 30]};
body = {[1 4 5 6 8 9 15], [5 7 8 9 13 20 30], [4 5 8 11 19 20 30 40 50 100]};
% Count of number of inputs
N = numel(head);
% Initialize the vector that holds the head elements that do not appear in other bodies
head_final_cell = cell(1,N);
% Loop over each head
for ii = 1:N
% Define an index that is 1:N, except for the current loop value
other_bodies_index = setxor(1:N,ii);
% Find index to head elements that are *not* in any other body, besides its own
head_not_in_other_body = not(ismember(head{ii},[body{other_bodies_index}]));
% For each head, fill the new cell array with the elements that do notappear in other bodies
head_final_cell{ii} = head{ii}(head_not_in_other_body);
end
% Concatenate all the individual head elements into one vector
head_final = [head_final_cell{:}];
Note that a lot of this code could be compressed into fewer lines, but I separated each step so that I could comment it, and hopefully help you understand what is going on.
