these variables, GHPtools computes the primes and complex conjugates through the
procedures GHPprime () and GHPconj ():
> GHPconj (GHPprime (rho+conjugate (rho)));
pl + pl
> GHPconj (Psi2);
> GHPprime (conjugate(mdn) (a));
mdn(a)
The {p, q} type of any quantity may be obtained by the use of the getpq function,
which returns p and q, in that order:
> getpq(Psi2);
0, O
> getpq(rhol);
-1, -1
> getpq(phi);
1pp, pq
Note that 4 is given the general type pp, qq. Before any computation begins it is often
useful to specify the spacetime in which subsequent computations are to take place by
specifying the value of the global variable spacetime:
> spacetime := typed;
spacetime := {@20 =0, #21 = 0, a = 0, #10 = 0, #22 = 0, II= 0, al = 0, #12 = 0, E = 0,
93 = 0, 94 = 0, 91 = 0, #11 = 0, 90 = 0, N1 = 0, a = 0, 000 = 0, 001 = 0,
002 = 0, O = 0, #12 = 0, #20 = 0, #11 = 0, #21 = 0, #22 = 0, al = 0, a = 0,
a = 0, 002 = 0, #10 = 0, N1 = 0, 90 = 0, 91 = 0, 93 = 0, 94 = 0, 000 = 0,
001 = 0}