Grouping does not affect disjunction or conjunction. Figure below shows equivalent diagrams.
Figure 1
Association Laws:
a + (b + c) = (a + b) + c
a x (b x c) = (a x b) x c
Mathematic Notation:
a ∪ (b ∪ c) = (a ∪ b) ∪ c
a ∩ (b ∩ c) = (a ∩ b) ∩ c
Logic Notation:
a ∧ (b ∧ c) = (a ∧ b) ∧ c
a ∨ (b ∨ c) = (a ∨ b) ∨ c
