Possible worlds semantics
Table of contents
In 1919, Irving Lewis axiomatically introduced the connective ⊰, rendered as ‘Necessarily if … then …’ or ‘It is impossible for … to be the case and for … not to be the case’, and called strict implication. It was explained as follows: “the relation of strict implication expresses precisely that relation which holds when valid deduction is possible and fails to hold when valid deduction is not possible” (Lewis & Langford 1932: 247).
References
Gamut, L. T. F.
Gerbrandy, J.
Gochet, P., E. Gregoire, P. Gribomont, G. Hulin, A. Pirotte, D. Roelants, D. Snyers, A. Thayse, M. Vauclair & P. Wolper
Gochet, P. & P. Gribomont
Groenendijk, J., M. Stokhof & F. Veltman
Hintikka, J.
Hodges, W.
Kaplan, D.
Lemmon, E. J.