diff --git a/ex7 b/ex7
index efd44636..db9cf6f7 100644
--- a/ex7
+++ b/ex7
@@ -44,7 +44,7 @@ GAS_PHASE 1 Fixed-pressure gas phase
 REACTION 1
         CH2O(NH3)0.07     1.0
         1. 2. 3. 4. 8. 16. 32 64. 125. 250. 500. 1000. mmol
-USER_GRAPH Example 7
+USER_GRAPH 1 Example 7
         -headings Fixed_Pressure: CH4 CO2 N2 H2O #Volume
         -chart_title "Gas Composition as a Result of Organic Decomposition"
         -axis_titles "ORGANIC MATTER REACTED, IN MILLIMOLES" "Log(PARTIAL PRESSURE, IN ATMOSPHERES)" "VOLUME, IN LITERS"
@@ -59,10 +59,10 @@ USER_GRAPH Example 7
   50 PLOT_XY mM_OM, SI("CO2(g)"), color = Red, symbol = XCross
   60 PLOT_XY mM_OM, SI("N2(g)"), color = Teal, symbol = XCross
   70 PLOT_XY mM_OM, SI("H2O(g)"), color = Blue, symbol = XCross
-  100 REM end of program  
+  100 REM end of program
   -end
 USER_GRAPH 2 Example 7
-        -headings  Fixed_P:...Pressure Fixed_P:...Volume 
+        -headings  Fixed_P:...Pressure Fixed_P:...Volume
         -chart_title "Total Gas Pressure and Volume as a Result of Organic Decomposition"
         -axis_titles "ORGANIC MATTER REACTED, IN MILLIMOLES" "Log(PRESSURE, IN ATMOSPHERES)" "VOLUME, IN LITERS"
         -axis_scale x_axis 1 1e3 auto auto log
@@ -72,27 +72,27 @@ USER_GRAPH 2 Example 7
   -start
   10 IF GAS("CH4(g)") < 1e-10 THEN GOTO 100
   20 mM_OM = RXN * 1e3
-  30 moles = (GAS("CH4(g)") + GAS("CO2(g)") + GAS("N2(g)") + GAS("H2O(g)")) 
+  30 moles = (GAS("CH4(g)") + GAS("CO2(g)") + GAS("N2(g)") + GAS("H2O(g)"))
   40 vol = moles * 0.08207 * TK / 1.1
-  50 PLOT_XY mM_OM, LOG10(1.1), color = Magenta, symbol = XCross 
+  50 PLOT_XY mM_OM, LOG10(1.1), color = Magenta, symbol = XCross
   60 PLOT_XY mM_OM, vol, color = Cyan, symbol = XCross, y_axis = 2
   100 REM end of program
-  -end  
+  -end
 END
 #  Simulation 3: Decomposition of organic matter, CH2O(NH3).07,
 #  at fixed volume of 23.19 L
 USE solution 1
 USE reaction 1
 GAS_PHASE 1 Fixed volume gas phase
-        -fixed_volume 
+        -fixed_volume
         -volume         23.19
         CO2(g)          0.0
         CH4(g)          0.0
         N2(g)           0.0
         H2O(g)          0.0
         -equilibrate 1
-USER_GRAPH
-        -headings Fixed_Volume: CH4 CO2 N2 H2O 
+USER_GRAPH 1
+        -headings Fixed_Volume: CH4 CO2 N2 H2O
   -start
   10 mM_OM = RXN * 1e3
   20 PLOT_XY -10, -10, line_width = 0, symbol_size = 0
@@ -105,8 +105,8 @@ USER_GRAPH 2
         -headings Fixed_V:...Pressure Fixed_V:...Volume
   -start
   10 mM_OM = RXN * 1e3
-  20 tot_p = 10^SI("CH4(g)") + 10^SI("CO2(g)") + 10^SI("N2(g)") + 10^SI("H2O(g)")
-  30 PLOT_XY mM_OM, LOG10(tot_p), color = Magenta, symbol = Circle 
-  40 PLOT_XY mM_OM, 23.19, color = Cyan, line_width = 1 symbol = Circle, y_axis = 2  
-  -end    
+  20 tot_p = SR("CH4(g)") + SR("CO2(g)") + SR("N2(g)") + SR("H2O(g)")
+  30 PLOT_XY mM_OM, LOG10(tot_p), color = Magenta, symbol = Circle
+  40 PLOT_XY mM_OM, 23.19, color = Cyan, line_width = 1 symbol = Circle, y_axis = 2
+  -end
 END