(Y-thetaXW)^2 given $(X,W)$ when flavor is set to
"learning".matrix of observations, see for instance the obs
argument of the function tmle.npvi.vector thetaXW of the conditional expectation of $Y$
given $(X,W)$, as currently estimated, evaluated at our observations.logical, kept for compatibility, which should be set to
TRUE (its default value). This requires that the result of each fit
be reduced in size (for a faster execution). Currently implemented only
for flavor learning.FALSE.