Update theory_set_reduction.md

dev_docs/theory_set_reduction.md

@@ -99,15 +99,15 @@ $$ \begin{bmatrix} M_{SN} & M_{SM} \\
  \begin{bmatrix} R_{SN}^T & 0_{MN}^T \\
                  0_{SM}^T & R_{MM}^T \end{bmatrix} 
                    \begin{Bmatrix}    q_S \\ 
-                                      q_M \end{Bmatrix}
+                                      q_M \end{Bmatrix} $$
 
 $$ \textsf{\color{red} start} $$
 
 $$ R_{MN} U_N + R_{MM} U_M $$
 
 $$ R_{MM} U_M = -R_{MN} U_N $$
 
-$$ U_M =  \underbrace{ -R_{MM}^{-1} R_{MN} }_\text{G_{MN}} U_N $$
+$$ U_M =   \underbrace{ -R_{MM}^{-1} R_{MN} }_\text{GMN} U_N $$
 
 $$ U_M =  -R_{MM}^{-1} R_{MN} U_N $$
 
@@ -119,10 +119,6 @@ where:
 
 $$ G_{MN} = -R_{MM}^{-1} R_{MN} $$
 
-use underbrace for GMN...
-
-$$  \underbrace{(x + 2)^3}_\text{text 1} $$
-
 $$ \textsf{\color{red} end} $$
 
 The bars over the N-set mass, stiffness and loads matrices are used for convenience to distinguish