Full Idea
If P and Q are any two propositions, the proposition that both P and Q is called the 'conjunction' of P and Q, and is written P∧Q.
Gist of Idea
That proposition that both P and Q is their 'conjunction', written P∧Q
Source
E.J. Lemmon (Beginning Logic [1965], 1.3)
Book Reference
Lemmon,E.J.: 'Beginning Logic' [Nelson 1979], p.19
A Reaction
[I use the more fashionable inverted-v '∧', rather than Lemmon's '&', which no longer seems to be used] P∧Q can also be defined as ¬(¬P∨¬Q)