First steps in infinitary modal logic

80 Views Asked by At

In modal logic, we have

$\Box(p\wedge q)\leftrightarrow\Box p\wedge\Box q$

but only

$\Box p\vee\Box q\rightarrow\Box(p\vee q)$,

where $\Box$ is the operator of necessity.

Do the same relations hold in infinitary modal logic, i.e. do we have

$\Box\bigwedge_{n\in\mathbb{N}}p_n\leftrightarrow\bigwedge_{n\in\mathbb{N}}\Box p_n$

but only

$\bigvee_{n\in\mathbb{N}}\Box p_n\rightarrow\Box\bigvee_{n\in\mathbb{N}}p_n$?