$$ \begin{array}{ll} |\forall y (y \in \dot{v} \Longrightarrow y \in \dot{x} \wedge \psi(y))|&= inf_{t \in dom(y)}(|y \in \dot{x}\wedge \varphi(y)| - |y \in \dot{v}|) \\ \\ &= \inf_{t \in dom(y)}(|y \in \dot{x}||\varphi(y)| - |y \in \dot{v}|) \\ \\ &= \inf_t (\sup_k \dot{x}(k)\cdot |y=k| \cdot |\varphi(y)| - \sup_g \dot{v}(g)\cdot |y=g|) \\ \\ &\geq \inf_t \sup_k |y=k|\cdot(\dot{x}(k)|\varphi(y)| - \dot{v}(k)) \\ \\ &= \inf_t \sup_k |y=k|\cdot(\dot{x}(k)|\varphi(y)| - \dot{x}(k)|\varphi(y)|) \\ \\ &= \inf_t \sup_k \emptyset = \inf_t \emptyset = 1 \\ \\ & \text{Assim} \space \inf_t (\sup_k \dot{x}(k)\cdot |y=k| \cdot |\varphi(y)| - \sup_g \dot{v}(g)\cdot |y=g|) = 1 \end{array} $$ $\square$