Extension of mappings into Banach spaces

This diploma thesis deals with extending continuous and uniformly continuous mappings. It studies Lebesgue's and Tietze's work in metric spaces through Urysohn's theorem in normal topological spaces, Kat etovs' papers about uniformly continuous functions up to Dugundji's theorem and relationship between continuous extending of pseudometrics and mappings. It connects the articles of nineteen mathematicians of the twentieth century, presents plenty of theorems in more general form and shows that they could be formulated earlier or proved in another way