Example 1: If A then B; if B then C; hence if A then C.
This is the connected chain of figure one.
Example 2: If A then C; under B the C relationship is denied; the extremes are separated.
This resembles the source's second-figure pattern, provided the negation has the appropriate scope and reference.
Example 3: If A then B; if A then C; the two predicates meet in the restricted common A case.
This illustrates the particular aspect of figure three, not “Every B is C.”