Past exam of the computer science course of the University of Oxford / 2015 / Logic and proof / 3 / a / D / Solution

Lucy's happiness is a single antecedent, while the conclusion applies to everyone:Since $x$ does not occur in the antecedent, this is equivalent to $\forall x[H(\ell )\to M(x)]$. The universal quantifier does not assert that everyone is happy; it is the merriness conclusion that is universal.