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\renewcommand{\not}{\neg}
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\newcommand{\lequiv}{\Leftrightarrow} %equivalence as logical connective
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\newcommand{\elc}{\models}  % semantic logical consequence
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{\bf Logic 1, WS 2017.
Homework 6, given Nov. 30, due Dec 7.}

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\noindent
Show by refutation, normal form, and resolution that $G$ is a semantical logical consequence of $F_1, F_2$.

$F_1:\ \ \exi_x(P[x] \and \all_y(R[y] \impl S[x, y]))$

$F_2:\ \ \all_x(P[x] \impl \all_y(Q[y] \impl \neg S[x, y])),$

$G:\ \ \all_x(R[x] \impl \neg Q[x]).$

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