consider the floating point system the distance between 1 and its right neighbour (ε1 ) is in matlab

In Matlab, the distance between 1 and its right neighbor (epsilon) can be computed using the eps function. This function returns the distance from 1.0 to the next larger double-precision number. Here's an example:

main.m
epsilon = eps(1);
disp(epsilon);
33 chars
3 lines

The output would be:

main.m
eps = 

     2.2204e-16
24 chars
4 lines

This means that in Matlab's floating-point system, the distance between 1 and its right neighbor (epsilon) is 2.2204e-16.