intermediate extension
korpuse vahelaiend, alamlaiend
olemus
korpuse K laiendi L alamkorpus, mis ühtlasi on korpuse K laiend
ülevaateid
https://math.stackexchange.com/questions/3966044/intermediate-field-extensions
https://en.wikipedia.org/wiki/Field_extension
http://www-users.math.umn.edu/~garrett/m/algebra/notes/22.pdf