Corrigendum for "A Systematic Approach to Programming" (26.04.2020)

- the binary decision tree for the operation INCH 
  described on p. 22 in the second last paragraph 
  ("The edge from INCH to FINDS is taken iff...")
  is incorrect. It is true that FINDS is the next
  operation if h is smaller than the cardinality
  of the current block. But if this is not the case
  then one does not necessarily continue with
  $\cong$ (isomorphic symbol). Instead one has to 
  check whether there is a block larger than k. If 
  this holds then one has to continue with the 
  operation NB, otherwise with $\cong$. 
  
  This implies an additional edge in the CFG from
  INCH to NB in Figure 8. 

  Thanks to Tien Hung Ngo for pointing this out.