diff --git a/slycot/analysis.py b/slycot/analysis.py
index 09120c97..172eab1c 100644
--- a/slycot/analysis.py
+++ b/slycot/analysis.py
@@ -322,47 +322,49 @@ def ab05nd(n1,m1,p1,n2,A1,B1,C1,D1,A2,B2,C2,D2,alpha=1.0,ldwork=None):
     return out[:-1]
 
 def ab07nd(n,m,A,B,C,D,ldwork=None):
-    """ A_i,B_i,C_i,D_i,rcond = ab07nd(n,m,A,B,C,D,[ldwork])
+    """ Ai,Bi,Ci,Di,rcond = ab07nd(n,m,A,B,C,D,[ldwork])
 
-    To compute the inverse (A_i,B_i,C_i,D_i) of a given system (A,B,C,D).
+    To compute the inverse (Ai,Bi,Ci,Di) of a given system (A,B,C,D).
 
-    Required arguments:
-        n : input int
-            The order of the state matrix A.  n >= 0.
-        m : input int
-            The number of system inputs and outputs.  m >= 0.
-        A : input rank-2 array('d') with bounds (n,n)
-            The leading n-by-n part of this array must contain the state matrix
-            A of the original system.
-        B : input rank-2 array('d') with bounds (n,m)
-            The leading n-by-m part of this array must contain the input matrix
-            B of the original system.
-        C : input rank-2 array('d') with bounds (m,n)
-            The leading m-by-n part of this array must contain the output matrix
-            C of the original system.
-        D : input rank-2 array('d') with bounds (m,m)
-            The leading m-by-m part of this array must contain the feedthrough
-            matrix D of the original system.
-    Optional arguments:
-        ldwork := None input int
-            The length of the cache array. The default value is max(1,4*m),
-            for better performance should be larger.
-    Return objects:
-        A_i : rank-2 array('d') with bounds (n,n)
-            The leading n-by-n part of this array contains the state matrix A_i
-            of the inverse system.
-        B_i : rank-2 array('d') with bounds (n,m)
-            The leading n-by-m part of this array contains the input matrix B_i
-            of the inverse system.
-        C_i : rank-2 array('d') with bounds (m,n)
-            The leading m-by-n part of this array contains the output matrix C_i
-            of the inverse system.
-        D_i : rank-2 array('d') with bounds (m,m)
-            The leading m-by-m part of this array contains the feedthrough
-            matrix D_i of the inverse system.
-        rcond : float
-            The estimated reciprocal condition number of the feedthrough matrix
-            D of the original system.
+    Parameters
+    ----------
+    n : int
+        The order of the state matrix A.  n >= 0.
+    m : int
+        The number of system inputs and outputs.  m >= 0.
+    A : (n,n) array_like
+        The leading n-by-n part of this array must contain the state matrix
+        A of the original system.
+    B : (n,m) array_like
+        The leading n-by-m part of this array must contain the input matrix
+        B of the original system.
+    C : (m,n) array_like
+        The leading m-by-n part of this array must contain the output matrix
+        C of the original system.
+    D : (m,m) array_like
+        The leading m-by-m part of this array must contain the feedthrough
+        matrix D of the original system.
+    ldwork : int, optional
+        The length of the cache array. The default value is max(1,4*m),
+        for better performance should be larger.
+
+    Returns
+    -------
+    Ai : (n,n) ndarray
+        The leading n-by-n part of this array contains the state matrix Ai
+        of the inverse system.
+    Bi : (n,m) ndarray
+        The leading n-by-m part of this array contains the input matrix Bi
+        of the inverse system.
+    Ci : (m,n) ndarray
+        The leading m-by-n part of this array contains the output matrix Ci
+        of the inverse system.
+    Di : (m,m) ndarray
+        The leading m-by-m part of this array contains the feedthrough
+        matrix Di of the inverse system.
+    rcond : float
+        The estimated reciprocal condition number of the feedthrough matrix
+        D of the original system.
 
     Warns
     -----