diff --git a/unify.tex b/unify.tex
index 247be21..450a96f 100644
--- a/unify.tex
+++ b/unify.tex
@@ -73,8 +73,8 @@ and a list of constraints $C' = \set{ \type{T} \lessdotCC \type{T}}$.
 The input constraints must be of the following format:
 
 \begin{tabular}{lcll}
-    $c $ &$::=$ & $\type{T} \lessdot \type{U}$ & Constraint \\
-    $\type{T}, \type{U}, \type{L} $ & $::=$ & $\tv{a} \mid \wtv{a} \mid \ntype{N}$ & Type variable or Wildcard Variable or Type \\
+    $c $ &$::=$ & $\type{T} \lessdot \type{T}, \type{T} \lessdotCC \type{T}$ & Constraint \\
+    $\type{T}, \type{U}, \type{L} $ & $::=$ & $\ntv{a} \mid \wtv{a} \mid \ntype{N}$ & Type variable or Wildcard Variable or Type \\
     $\ntype{N}, \ntype{S}$ & $::=$ & $\wctype{\overline{\wildcard{X}{U}{L}}}{C}{\ol{T}} $ & Class Type \\
 \end{tabular}\\[0.5em]
 
@@ -110,7 +110,8 @@ The \unify{} algorithm internally uses the following data types:
 \begin{tabular}{lcll}
     $C $ &$::=$ &$\overline{c}$ & Constraint set \\
     $c $ &$::=$ & $\type{T} \lessdot \type{T} \mid \type{T} \lessdotCC \type{T} \mid \type{T} \doteq \type{T}$ & Constraint \\
-    $\type{T}, \type{U}, \type{L} $ & $::=$ & $\tv{a} \mid \wtv{a} \mid \gtype{G}$ & Type variable or Type \\
+    $\type{T}, \type{U}, \type{L} $ & $::=$ & $\tv{a} \mid \gtype{G}$ & Type placeholder or Type \\
+    $\tv{a}$ & $::=$ & $\ntv{a} \mid \wtv{a}$ & Normal and wildcard type placeholder \\
     $\gtype{G}$ & $::=$ & $\type{X} \mid \ntype{N}$ & Wildcard, or Class Type \\
     $\ntype{N}, \ntype{S}$ & $::=$ & $\wctype{\triangle}{C}{\ol{T}} $ & Class Type \\
     $\triangle$ & $::=$ & $\overline{\wtype{W}}$ & Wildcard Environment \\