Complex sentence: In mathematics, the uniform boundedness principle or Banach-Steinhaus Theorem is one of the fundamental results in functional analysis and, together with the Hahn-Banach theorem and the open mapping theorem, considered one of the cornerstones of the field.
Split into simpler sentences: In mathematics, the uniform boundedness principle or Banach-Steinhaus Theorem is one of the fundamental results in functional analysis. Together with the Hahn-Banach theorem and the open mapping theorem, it is considered one of the cornerstones of the field.