  We describe the techniques used in pulsar timing observations, and show how
these observations may be applied to tests of strong-field general relativity
for double-neutron-star binary systems. We describe the tests of GR resulting
from the PSRs B1913+16 and B1534+12 systems. For the latter pulsar, 5
"Post-Keplerian" timing parameters are measurable, including the orbital period
derivative and the two Shapiro delay parameters.
