Interval Arithmetic Toolbox for Matlab

				function r = add(a,b)
				
				%ADD computes an inclusion (interval) of the sum of two matrices.
				%
				%b4m - datatype interval    Version 1.02    (c) 26.2.1998 Jens Zemke
				%
				%   DESCRIPTION:
				%     'add' is called
				%
				%         r = add(a,b)
				%
				%     and computes the interval matrix r
				%     inlcuding the true result.
				%
				%     The operations on the datatype interval
				%     are based on BIAS by Olaf Knueppel.
				%
				%   SEE ALSO:
				%     interval: plus.
				%     double: sub, mul, div.
				
				global b4m_DouBLe b4m_INTerval
				
				b4m_DouBLe = 1;
				
				r.val = bias_add(b4m_DouBLe, a, b4m_DouBLe, b);
				r = interval(r);