def s2(Q,P,B) {
  return [Q+B/P,P];
}

def t2(Q,P,B) {
  return [-Q,-P+2*Q^2+t];
}

def p2check(F,B) {
  G=-diff(F,[t,t])+2*F^3+t*F+B-1/2;
  return red(G);
}

def test() {
  Y=0;
  print(p2check(Y,1/2));
  Y = s2(0,t/2,1/2);
  Y0=subst(Y[0],t,x);
  print("Solution is ",0); print(Y0);
  gnuplot.gnuplot("plot [-5:5] "+rtostr(Y0)+";");
  print(p2check(Y[0],-1/2));
}

def test2() {
  Y=0;
  Y = s2(0,t/2,1/2);
  Y = t2(Y[0],Y[1],-1/2);
  Y = s2(Y[0],Y[1],3/2);
  print(p2check(Y[0],-3/2));
  Y0=subst(Y[0],t,x);
  print("Solution is ",0); print(Y0);
  ctrl("fortran_output",1);
  gnuplot.gnuplot("plot [0.2:20] "+rtostr(Y0)+";");
  ctrl("fortran_output",0);
}


end$