We enlarge the problem of valuations of triads on so called lines. A line in an $e$-structure $𝔸=\langle A,F,E\rangle$ (it means that $\langle A,F\rangle$ is a semigroup and $E$ is an automorphism or an antiautomorphism on $\langle A,F\rangle$ such that $E\circ E=\mathrm{𝐈𝐝}\upharpoonright A$) is, generally, a sequence $𝔸\upharpoonright B$, $𝔸\upharpoonright U_c$, $c\in \mathrm{𝐅𝐙}$ (where $\mathrm{𝐅𝐙}$ is the class of finite integers) of substructures of $𝔸$ such that $B\subseteq U_c\subseteq U_d$ holds for each $c\le d$. We denote this line as $𝔸{(U_c,B)}_{c\in \mathrm{𝐅𝐙}}$ and we say that a mapping $H$ is a valuation of the line $𝔸{(U_c,B)}_{c\in \mathrm{𝐅𝐙}}$ in a line $\widehat{𝔸}{({\widehat{U}}_c,\widehat{B})}_{c\in \mathrm{𝐅𝐙}}$ if it is, for each $c\in \mathrm{𝐅𝐙}$, a valuation of the triad $𝔸(U_c,B)$ in $\widehat{𝔸}({\widehat{U}}_c,\widehat{B})$. Some theorems on an existence of...

Various characterizations of realcompactness are transferred to uniform spaces giving non-equivalent concepts. Their properties, relations and characterizations are described in this paper. A Shirota-like characterization of certain uniform realcompactness proved by Garrido and Meroño for metrizable spaces is generalized to uniform spaces. The paper may be considered as a unifying survey of known results with some new results added.