Conbinational group instead of regestered group

Where do you see variable classification as registered or combinational? All variables assigned in a clocked always block are inferring registers, so the variables in the example codes. However, due to the usage of blocking assignments, some variables are also used to hold combinational intermediate results, e.g. bit in the last block. The registered value is first increased, than the new value is immediately used as index and in a compare operation. The last assigned value is written to register again when exiting the always block.