The method of the degrees of freedom.
OptionaldfSatterthwaite's degrees of freedom (R's df; not with ddf: "lme4").
Estimates (R's Estimate).
R's messages (none so far).
The names of the fixed effects (R's row names).
OptionalpTwo-sided p-values (R's Pr(>|t|); not with ddf: "lme4").
Standard errors (R's Std. Error).
t statistics (R's t value).
R's warnings: those about the eigenvalues of the Hessian of the deviance in the variance parameters.
Result of lmerSummary: the coefficient table of lmerTest's
summary().