Problem Display
PID: 10091 (8/8/8/3N1B2/1B6/1R1NPp1K/k1qp1Q2/1R6 w - - 0 1)

Ling, John Francis

4th Prize, BCPS Ring Ty., 1962

8/8/8/3N1B2/1B6/1R1NPp1K/k1qp1Q2/1R6

#2

9 + 4


3174 The Two-move Chess Problem Tradition and Development 1966

SOLUTION


  • SOUND
  • Sets
    • 1...Qxb1
      • 2.Ra3#
    • 1...Qd1
      • 2.Sc3#
      • 2.R3b2#
    • 1...Qxb3
      • 2.Sc1#
    • 1...Qxd3
      • 2.R3b2#
    • 1...Qc1
      • 2.Sxc1#
    • 1...Qb2
      • 2.R3xb2#
    • 1...Qc3
      • 2.Sxc3#
    • 1...Qc4
      • 2.R3b2#
    • 1...Qc5
      • 2.R3b2#
    • 1...Qc6
      • 2.R3b2#
    • 1...Qc7
      • 2.R3b2#
    • 1...Qc8
      • 2.R3b2#
    • 1...d1Q
      • 2.Sc3#
    • 1...d1S
      • 2.Sc1#
    • 1...d1B
      • 2.Sc1#
      • 2.Sc3#
    • 1...d1R
      • 2.Sc3#
      • 2.Qxc2#
  • Tries
    • 1.Kh2?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#
      • 1...Qc7+!
    • 1.Kg3?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#
      • 1...Qc7+!
    • 1.Kg4?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#
      • 1...Qc4+!
    • 1.Kh4?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#
      • 1...Qc4+!
    • 1.Sc1+?
      • 1...dxc1Q
        • 2.Sc3#
      • 1...dxc1S
        • 2.Sc3#
        • 2.Qxc2#
      • 1...dxc1B
        • 2.Sc3#
      • 1...dxc1R
        • 2.Sc3#
      • 1...Qxc1!
    • 1.Bc5?
      • threat
        • 2.S3b4#
        • 2.S5b4#
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.Sb4#
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qxc5!
    • 1.Bd6?
      • threat
        • 2.S3b4#
        • 2.S5b4#
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.Sb4#
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5!
    • 1.Be7?
      • threat
        • 2.S3b4#
        • 2.S5b4#
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.Sb4#
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5!
    • 1.Bf8?
      • threat
        • 2.S3b4#
        • 2.S5b4#
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.Sb4#
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5!
    • 1.Be4?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8+!
    • 1.Bg4?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#
      • 1...Qxb3!
    • 1.Bg6?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8+!
    • 1.Bd7?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#
      • 1...Qxb3!
    • 1.Bh7?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8+!
    • 1.R1b2+?
      • 1...Ka1
        • 2.Ra3#
      • 1...Qxb2!
    • 1.Qxd2?
      • threat
        • 2.Sc1#
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qb2
        • 2.Sc1#
        • 2.R3xb2#
        • 2.Qxb2#
      • 1...Qxd2!
    • 1.Qh2?
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc1#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#
      • 1...f2!
    • 1.e4?
      • threat
        • 2.Qa7#
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#
      • 1...Qxb3!
  • Keys
    • 1.Be6!
      • 1...Qxb1
        • 2.Ra3#
      • 1...Qxb3
        • 2.Sc3#
      • 1...Qxd3
        • 2.R3b2#
      • 1...Qb2
        • 2.R3xb2#
      • 1...d1Q
        • 2.Sc3#
      • 1...d1S
        • 2.Sc1#
      • 1...d1B
        • 2.Sc1#
        • 2.Sc3#
      • 1...d1R
        • 2.Sc3#
        • 2.Qxc2#
      • 1...Qd1
        • 2.Sc3#
        • 2.R3b2#
      • 1...Qc1
        • 2.Sxc1#
      • 1...Qc3
        • 2.Sxc3#
      • 1...Qc4
        • 2.R3b2#
      • 1...Qc5
        • 2.R3b2#
      • 1...Qc6
        • 2.R3b2#
      • 1...Qc7
        • 2.R3b2#
      • 1...Qc8
        • 2.R3b2#

FEATURES


  • Static
    • TYPE = MUTATE
    • CHANGED MATES = 1
    • ADDED MATES = 0
    • REMOVED MATES = 0
  • Sets
    • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
    • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
    • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
    • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
    • Q(b);N_GUARD::R1(C),XQ(b)
    • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
    • Q(b);N_GUARD,P_SPINP(c)::R1(C)
    • Q(b);N_GUARD,P_PINB(I),P_SPINP(c)::R1(C)
    • P(c);P_SPINQ(b)::S(H)
    • P(c);N_GUARD,P_SPINQ(b)::S(D)
  • Tries
    • Try
      • K(F);P-FLIGHT
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_PINQ(B),P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_PINQ(B),P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);CHECK,P_SPINP(c)
    • Try
      • K(F);P-FLIGHT
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);CHECK,P_SPINP(c)
    • Try
      • K(F);S_FLIGHT
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
        • Q(b);N_GUARD,P_PINB(I),P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);CHECK,P_SPINP(c)
    • Try
      • K(F);P-FLIGHT
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);CHECK,P_SPINP(c)
    • Try
      • S(D);CHECK
      • Vars
        • P(c);P_SPINQ(b),XS(D)::S(H)
      • Refutation
        • Q(b);P_SPINP(c),XS(D)
    • Try
      • B(G);
      • Threat
        • DUALS(2)
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);P_SPINP(c),XB(G)
    • Try
      • B(G);
      • Threat
        • DUALS(2)
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);P_SPINP(c)
    • Try
      • B(G);
      • Threat
        • DUALS(2)
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);P_SPINP(c)
    • Try
      • B(G);
      • Threat
        • DUALS(2)
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);P_SPINP(c)
    • Try
      • B(I);
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);CHECK,P_SPINP(c)
    • Try
      • B(I);
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
        • Q(b);N_GUARD,P_PINB(I),P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);P_SPINP(c),XR(C)
    • Try
      • B(I);
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);CHECK,P_SPINP(c)
    • Try
      • B(I);
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
        • Q(b);N_GUARD,P_PINB(I),P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);P_SPINP(c),XR(C)
    • Try
      • B(I);
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);CHECK,P_SPINP(c)
    • Try
      • R(A);CHECK
      • Vars
        • K(a);P-FLIGHT::R(C)
      • Refutation
        • Q(b);XR(A)
    • Try
      • Q(B);P_PINQ(b),XP(c)
      • Threat
        • DUALS(3)
      • Refutation
        • Q(b);N_SPINQ(b),XQ(B)
    • Try
      • Q(B);
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(D)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • P(c);P_SPINQ(b)::S(H)
        • P(c);N_GUARD,P_SPINQ(b)::S(D)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
        • Q(b);N_GUARD,P_PINB(I),P_SPINP(c)::R1(C)
      • Refutation
        • P(d);
    • Try
      • P(E);
      • Threat
        • QAR(B)
      • Vars
        • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
        • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
        • Q(b);N_GUARD::R1(C),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
        • Q(b);N_GUARD,P_SPINP(c)::R1(C)
        • Q(b);N_GUARD,P_PINB(I),P_SPINP(c)::R1(C)
      • Refutation
        • Q(b);P_SPINP(c),XR(C)
  • Actual
    • B(I);
    • Vars
      • Q(b);P_SPINP(c),SBLOCK,XR(A)::R1(C)
      • Q(b);N_GUARD,P_SPINP(c),XR(C)::S(H)
      • Q(b);N_GUARD,P_SPINP(c),XS(D)::R1(C)
      • Q(b);N_GUARD::R1(C),XQ(b)
      • P(c);P_SPINQ(b)::S(H)
      • P(c);N_GUARD,P_SPINQ(b)::S(D)
      • Q(b);N_GUARD,P_SPINP(c)::S(D),XQ(b)
      • Q(b);N_GUARD,P_SPINP(c)::S(H),XQ(b)
      • Q(b);N_GUARD,P_SPINP(c)::R1(C)
      • Q(b);N_GUARD,P_PINB(I),P_SPINP(c)::R1(C)


Developed and maintained by Brian Stephenson.
Implemented with HTML5, MySQL, Perl (with, inter alia, CGI::Simple, HTML::Template & XML::LibXML) & CSS/Javascript (jQuery, Bootstrap & DataTables).