Contradictions arise mostly at the beginning and at the end of a theoretical construction.
If the meaning of words is not fixed a proposition and its negation can both be true. And, as it is well known, a theory in spite of the axiomatic fixation of its concepts must contain inconsistencies if its means of expression are sufficiently rich. The minimal logic avoids this logical principle but from a contradiction we can deduce in it the negation of every proposition. By the way these systems contain logical laws which Hegelians in spite of their famous rejection of the principle of contradiction must acknowledge as valid. Equivalence of C n and CG n .