MATLAB: How create cross product in fcn simulink matlab

cross producterrorMATLABsimulinkvector

hi,i want to simulate a system physical in simulink matlab rs2015. i read from website mathworks cross product i.e. using this:
t1 = [2,3,1];
 t2 = [3,1,2];
 C = A(:,t1).*B(:,t2)-A(:,t2).*B(:,t1);
please see image simulink : please see image
fcn function is defined:
function C = fcn(A,  B)
 t1 = [2,3,1];
 t2 = [3,1,2];
C = A(:,t1).*B(:,t2)-A(:,t2).*B(:,t1);
now wehn i run it:it returns this errors:
   Attempted to access index 2 of data A.
MATLAB function eML_blk_kernel in MATLAB Function MATLAB Function: C = A(:,t1).*B(:,t2)-A(:,t2).*B(:,t1);
                                                                           ^^
The valid index range is 1 to 1.
This error will stop the simulation.
Component: MATLAB Function | Category: Runtime error
An error occurred while running the simulation and the simulation was terminated
Simulation stopped because of a runtime error: out of bounds.
Component: Simulink | Category: Block error
how we can defined a function that is can operate with vector concatenate
thanks for attention
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