Chess Board
[ECO code E46]
NIMZO-INDIAN DEF. - Rubinstein Sys.
Reshevsky Var. - The Simagin Variation
White's QRPawn out to QR3(a3) attacked to dislodge the dark bishop on QKt4(b4).
Black's dark Bishop retreats to Q3(d6). Tends to continue 7.PxP..PxP [or 7..KtxP] with equality. B-Alt. 
    White  Black	White  Black
 1. P-Q4   Kt-KB3    6.	P-QR3  B-Q3
 2. P-QB4  P-K3
 3. Kt-QB3 B-Kt5
 4. P-K3   0-0
 5. KKt-K2 P-Q4
Example ends: Undo or Jump or Clear