Should any section, paragraph, sentence, clause, phrase or word of this code be declared invalid or unconstitutional by a court of competent jurisdiction, such invalidity or unconstitutionality shall not affect any of the remaining words, phrases, clauses, sentences, paragraphs or sections of this code, since the same would have been enacted by the board of trustees without the incorporation in this code of any such invalid or unconstitutional words, phrase, clause, sentence, paragraph or section.