 Usage:  x = invfwt2 (c, l, h, a)  
 
 Input:

  c                      n x n matrix, wavelet coefficients, retrieved e.g. by fwt2. 
                         n has to be a power of 2 
                         
  l                      integer, l^2 is the number of the father wavelets coeffients 
                         
  h                      m x 1 vector, wavelet basis 
                         
  a                      integer, 0,1,2,3,... see notes 
                         
 Output:

  x                      n x n matrix, 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
