; initially A contains the arithmetical decoder state (up to 7 bits) and C might contain a carry to be added to it
loop:
	LDX databyte
	ADC ari_lo, X  ; these table entries contain 7 bits each, too - erroneous entries contain $FF and thus might set C
	ROL            ; since we used bits 0..6 so far bit 7 contains the carry. Shift it into the C flag.
                       ; (And shift the C flag, which is hopefully set upon errors due to adding $FF (TODO change offsets to ensure that's actually the case), into the now-unused bit 0 of tmp.)
	STA tmp        ; Don't store the first decoded 7 bits but use them for filling the next 7-bit values
	LDA ari_hi, X  ; Fetch upper 7 arith bits

	; repeat the following block 7 times

	LDX databyte
	ADC ari_lo, X  ; Same here - add 7 lower bits of table entry for GCR byte
	ROL tmp	       ; Get a data bit and store error bit
	; in the last iteration tmp contains error flags from each of the 8 steps so we could thus BNE to an error handler
	ROL             ; Combine the 7 decoded data bits with the additional bit, also push the carry from bit 7 to flag C
	STA result+i, Y ; and store decoded byte
	LDA ari_hi, X   ; Get 7 upper bits of table entry
	
	; end repeat

future[1..N] = 1;
for(bits = 1 to M) {
	present[O1] = future[O2] + future[Z1];
	present[O2] = future[O3] + future[Z1];
	present[O3] = future[O4] + future[Z1];
	present[O4] = future[O5] + future[Z1];
	present[O5] = future[O6] + future[Z1];
	present[O6] = future[O7] + future[Z1];
	present[O7] = future[O8] + future[Z1];
	present[O8] = future[O9] + future[Z1];
	present[O9] = future[Z1];
	present[Z1] = future[O1] + future[Z2];
	present[Z2] = future[O1];
	future = present;
}
result = log2(present[O1]) / bits;