Now if we take our letters thus,
A = Iron, B = metal, C = good conductor of electricity, D = useful for telegraphic purposes,
the premises will assume the forms
| A = AB, | (1) |
| B = BC, | (2) |
| C = CD. | (3) |
For B in (1) we can substitute its equivalent in (2) obtaining, as before,
A = ABC.
Substituting for C in this intermediate result its equivalent as given in (3), we obtain the complete conclusion
| A = ABCD. | (4) |
The full interpretation is that Iron is iron, metal, good conductor of electricity, useful for telegraphic purposes, which is abridged in common language by the ellipsis of the circumstances which are not of immediate importance.
Instead of all the propositions being exactly of the same kind as in the last example, we may have a series of premises of various character; for instance,