mecànica tensorial y relativitat general

d_{ttt}[1+x(t)]/(d_{t}[1+x]d_{t}[1+x]d_{t}[1+y])+( 1+x(t) ) = d_{t}[x]
d_{ttt}[1+y(t)]/(d_{t}[1+y]d_{t}[1+y]d_{t}[1+x])+( 1+y(t) ) = (-1)·d_{t}[y]


R^{i}_{iij}+m^{i} = T^{i}
R^{j}_{jji}+m^{j} = (-1)·T^{j}


x(t) = e^{t}
y(t) = e^{-t}