Science fiction (Wikipedia)
Science fiction (sometimes shortened to sf or sci-fi) is a genre of speculative fiction, which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel universes, and extraterrestrial life. Science fiction can trace its roots to ancient mythology. It is related to fantasy, horror, and superhero fiction and contains many subgenres. Its exact definition has long been disputed among authors, critics, scholars, and readers.Action film (Wikipedia)
The action film is a film genre that predominantly features chase sequences, fights, shootouts, explosions, and stunt work. The specifics of what constitutes an action film has been in scholarly debate since the 1980s. While some scholars such as David Bordwell suggested they were films that favor spectacle to storytelling, others such as Geoff King stated they allow the scenes of spectacle to be attuned to story telling. Action films are often hybrid with other genres, mixing into various forms ranging to adventure films, comedy films, science fiction films, and horror films.- Sequence (Wikipedia)
In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called elements, or terms). The number of elements (possibly infinite) is called the length of the sequence. Unlike a set, the same elements can appear multiple times at different positions in a sequence, and unlike a set, the order does matter. Formally, a sequence can be defined as a function from natural numbers (the positions of elements in the sequence) to the elements at each position. The notion of a sequence can be generalized to an indexed family, defined as a function from an arbitrary index set.