I get this error 'Undefined function 'B' for input arguments of type 'char'.' on running the following the code. What am I doing wrong?

B := hfarray(1..2,1..2,[Haa,Hab],[Hba,Hbb]);

Haa := hfarray(1..n);

Hab := hfarray(1..n);

Hba := hfarray(1..n);

Hbb := hfarray(1..n);

[Matt J]

The code you have shown does not look like MATLAB code.

[Friedrich]

Looks like MUPAD code.