You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: learn.m
    path of file: ./repos/PlatEMO/PlatEMO/Algorithms/Multi-objective optimization/CLIA/iSVM
    
    the code of the file until where you have to start completion: % LEARN - Increments the specified example into the current SVM solution.  
%         Assumes alpha_c = 0 initially.
%
% Syntax: nstatus = learn(indc,rflag)
%
% nstatus: new status for indc
%    indc: index of the example to learn
%   rflag: flag indicating whether or not to check if any reserve vectors
%          become margin
    
function nstatus = learn(indc,rflag)

% flags for example state
MARGIN    = 1;
ERROR     = 2;
RESERVE   = 3;
UNLEARNED = 4;

% define global variables 
global a;             % alpha coefficients
global b;             % bias
global C;             % regularization parameters
global deps;          % jitter factor in kernel matrix
global g;             % partial derivatives of cost function w.r.t. alpha coefficients
global ind;           % structure containing indices of margin, error, reserve and unlearned vectors
global perturbations; % number of perturbations
global Q;             % extend