text: **Propositional logic**
  
  Propositional logic comprises formal systems in which formulae are built from atomic propositions using 
  logical connectives. For instance, propositional logic represents the conjunction of two atomic 
  propositions 
  . Unlike predicate logic where terms and predicates 
  are the smallest units, propositional logic takes full propositions with truth values as its most basic 
  component.[121] Thus, propositional logics can only represent logical relationships that arise from the 
  way complex propositions are built from simpler ones. But it cannot represent inferences that result from 
  the inner structure of a proposition.[122] 
  
   and   as the complex formula 