Hi

To completly solving this puzzle i used 2 strategies 3 times forcing chain (AIC) and at end Medusa 3D

In notation i use letters from A to I for rows and digits 1-9 for columns.

Lets start.

Firs chain is:

IF -7B3->+7(B 3/6)-> -7(A/C5)->+7G5->-2/9 G5->+2G7->-2H7->+9H7->-9H4->+9J5->-9A5->+9A1-7A1->+7B3 if 7 is removed from B3 chain implies tha must be. Other candidates in B3 must be false.

After all possible elimanations in G1 is last candidate 7 in col 1 so he must be true.

Second chain is:

If -3J1->+9J1->-9A1->+4A1->-4A3->+2A3->-2A8->+2C8->-7C8->+7C5-3C5->+3J5->-3J1

So we have continous loop this chain implies this eliminations: -2A5 -2C5 -3J2 Now in B6 is last cand 2 so must be true In A/C3 is pointing par 2 after all possible eliminations ( im not telling about all of them everyone must find by self) next step.

Thirth and last chain is:

IF -2J2->+9J2->-9J1->+9A1-4A1->+4A3->-4H3->+4H2->-2H2->+2J2

IF 2 removed from J2 chain emplies that must be.

Now after all possible elimintiions diagram should have about 20 unsolved cells and in most of them only 2 candidates so now is best moment for medusa3d. If someone dont khow what is it .....well in internet is all.

Medusa leds to contradiction in cell H2 and in this same momemnt we khnowing true values for 95% unsolved cells . Medusa3D is super

Ok thats all i hope is no mostakes in chains notation if are sorry:)

Enjoyed