Definition:Johansson's Minimal Logic

 Johansson's minimal logic is a subbranch of propositional logic of the intuitionist school.

The philosophical position behind it is that it may be the case that the proof rules: do not hold.
 * The Law of the Excluded Middle (a statement is either true or false)
 * The Rule of Explosion (from a contradiction anything can be deduced)

Thus this philosophical school allows for the foundation of the study of fuzzy logic.

Also known as
This system is also known as Johansson's minimal calculus.