diff --git a/logic.sty b/logic.sty
index 5f0f75a..7c3a7af 100644
--- a/logic.sty
+++ b/logic.sty
@@ -127,6 +127,7 @@
 
 
 \DeclareSimpleMathOperator{CH}
+\DeclareSimpleMathOperator{GCH}
 \DeclareSimpleMathOperator{DC}
 \DeclareSimpleMathOperator{Ord}
 \DeclareSimpleMathOperator{OR} % Ordinals
diff --git a/logic2.tex b/logic2.tex
index 319b38c..aed93db 100644
--- a/logic2.tex
+++ b/logic2.tex
@@ -40,6 +40,7 @@
 \input{inputs/lecture_14}
 \input{inputs/lecture_15}
 \input{inputs/lecture_16}
+\input{inputs/lecture_17}
 
 
 \cleardoublepage