diff --git a/include/mp/flat/constr_algebraic.h b/include/mp/flat/constr_algebraic.h
index 96f7339b2..7bc68d856 100644
--- a/include/mp/flat/constr_algebraic.h
+++ b/include/mp/flat/constr_algebraic.h
@@ -7,6 +7,7 @@
 
 #include <string>
 #include <cmath>
+#include <cfloat>
 
 #include "mp/flat/constr_base.h"
 #include "mp/flat/expr_quadratic.h"
@@ -247,7 +248,9 @@ inline void WriteJSON(JSONW jw,
 /// Write alg con range
 inline void WriteJSON(JSONW jw,
                       const AlgConRange& acr) {
-  jw << acr.lb() << acr.ub();
+  jw
+      << (acr.lb() < -DBL_MAX ? -DBL_MAX : acr.lb())
+      << (acr.ub() > DBL_MAX ? DBL_MAX : acr.ub());
 }
 
 /// Write alg con rhs
diff --git a/include/mp/flat/converter_model.h b/include/mp/flat/converter_model.h
index 2903645d7..6afdd0908 100644
--- a/include/mp/flat/converter_model.h
+++ b/include/mp/flat/converter_model.h
@@ -5,6 +5,7 @@
 #include <vector>
 #include <algorithm>
 #include <cmath>
+#include <cfloat>
 
 #include "mp/flat/obj_std.h"
 #include "mp/flat/constr_std.h"
@@ -89,7 +90,9 @@ class FlatModel
         jw["VAR_index"] = i_actual;
         if (var_names_storage_.size() > i)
           jw["name"] = var_names_[i];
-        jw["bounds"] << lbs[i] << ubs[i];
+        jw["bounds"]
+            << (lbs[i] < -DBL_MAX ? -DBL_MAX : lbs[i])
+            << (ubs[i] > DBL_MAX ? DBL_MAX : ubs[i]);
         jw["type"] = (int)types[i];
         jw["is_from_nl"] = (int)is_var_original(i_actual);
       }
diff --git a/support/modelexplore/modelexplore.py b/support/modelexplore/modelexplore.py
index 6fcfaee7e..abd38cb9f 100644
--- a/support/modelexplore/modelexplore.py
+++ b/support/modelexplore/modelexplore.py
@@ -1,26 +1,53 @@
 
 import streamlit as st
 
-# To work in st 1.30.1, see
-# https://discuss.streamlit.io/t/axioserror-request-failed-with-status-code-403/38112/13
-input_file = st.file_uploader("Model file (JSONL)")
+from scripts.python.explorer import ModelExplorer
+from scripts.python.modelreader import ReadExplorerModel
+from scripts.python.matcher import MatchSubmodel
+
+# To work with local files in st 1.30.1, see
+# https://discuss.streamlit.io/t/axioserror-request-failed-with-status-code-403/38112/13.
+# The corresponding settings should not be used on a server.
+uploader = st.file_uploader("Model file (JSONL)")
 
 left_column, right_column = st.columns(2)
 
 # You can use a column just like st.sidebar:
 srch = left_column.text_input('Search pattern:')
 
-# Or even better, call Streamlit functions inside a "with" block:
 fwd = right_column.checkbox('Add descendants', disabled=True)
 bwd = right_column.checkbox('Add ancestors', disabled=True)
 
-if input_file is not None:
+explorer = ModelExplorer()
+
+# Cache the reading function
+@st.cache_data
+def ReadModel(uploader):
+  return ReadExplorerModel(uploader)
+
+# Cache the matching function?
+# @st.cache_data  Need cacheable Model.
+def MatchSelection(m, srch, fwd, bwd):
+  return MatchSubmodel(m, srch, fwd, bwd)
+
+# Write dictionary of entries
+def WriteDict(d):
+  for k, v in d.items():
+    with st.expander("""### """ + k):
+      st.write(v)
+
+# Or even better, call Streamlit functions inside a "with" block:
+if uploader is not None:
+  model = ReadModel(uploader)
+  subm1, subm2 = MatchSelection(model, srch, fwd, bwd)
+  bytes1_data = subm1.GetData()
+  bytes2_data = subm2.GetData()
   with left_column:
-    bytes_data = input_file.read()
-    st.write("NL model")
-    st.write(bytes_data)
+    st.write("""## NL model""")
+    WriteDict(bytes1_data)
   with right_column:
-    st.write("Flat model")
+    st.write("""## Flat model""")
+    WriteDict(bytes2_data)
 else:
   with left_column:
     st.write("No file selected.")
diff --git a/support/modelexplore/scripts/python/graph.py b/support/modelexplore/scripts/python/graph.py
new file mode 100644
index 000000000..ecb9549b9
--- /dev/null
+++ b/support/modelexplore/scripts/python/graph.py
@@ -0,0 +1,23 @@
+# This Python file uses the following encoding: utf-8
+
+# if __name__ == "__main__":
+#     pass
+
+class DiGraph:
+  """
+  A simple digraph or a wrapper around some graph library
+  """
+
+  def __init__(self):
+    self._nodes = []
+    self._arcs = []
+
+  def AddNode(self, data=None):
+    self._nodes.append(data)
+    return len(self._nodes)-1
+
+  def GetNode(self, idx):
+    return self._nodes[idx]
+
+  def ToText(self):
+    return str(self._nodes)
diff --git a/support/modelexplore/scripts/python/matcher.py b/support/modelexplore/scripts/python/matcher.py
new file mode 100644
index 000000000..2c74903a3
--- /dev/null
+++ b/support/modelexplore/scripts/python/matcher.py
@@ -0,0 +1,28 @@
+# This Python file uses the following encoding: utf-8
+
+# if __name__ == "__main__":
+#     pass
+
+from scripts.python.model import Model
+from scripts.python.modelview import ModelView
+
+class Matcher:
+  """
+  Selects a submodel
+  """
+
+  def __init__(self):
+    self.data = None
+
+
+def MatchSubmodel(m: Model, patt: str, fwd: bool, bwd: bool):
+  """
+  Match a submodel containg the \a pattern,
+  optionally extended by forward/backward
+  reformulation graph search
+  """
+  mv1 = ModelView()
+  mv2 = ModelView()
+  mv1.SetData(m.MatchOrigModel(patt))
+  mv2.SetData(m.MatchFinalModel(patt))
+  return mv1, mv2
diff --git a/support/modelexplore/scripts/python/model.py b/support/modelexplore/scripts/python/model.py
new file mode 100644
index 000000000..3e6c56fdf
--- /dev/null
+++ b/support/modelexplore/scripts/python/model.py
@@ -0,0 +1,115 @@
+# This Python file uses the following encoding: utf-8
+
+# if __name__ == "__main__":
+#     pass
+
+import streamlit as st
+
+from scripts.python.graph import DiGraph
+
+class Model:
+  """
+  An optimization model with conversion
+  graph
+  """
+
+  def __init__(self):
+    self._graph = DiGraph()    ## Underlyng graph
+
+    self._vars = []            ## Pointers to various parts of the graph
+    self._cons_NL_all = []
+    self._cons_NL = {        ## NL + SOS
+      "All" : [],
+      #"Linear" : [],
+      #"Logical": [],
+      "SOS": []}
+    self._cons_Flat = {}
+    self._cons_Flat_Group = {}
+    self._objs_NL = []
+    self._objs = []
+
+  def UpdateVar(self, idx, data):
+    self._updateNodeData(self._vars, idx, data)
+
+  def UpdateNLObj(self, idx, data):
+    self._updateNodeData(self._objs_NL, idx, data)
+
+  def UpdateFlatObj(self, idx, data):
+    self._updateNodeData(self._objs, idx, data)
+
+  def UpdateNLCon(self, type, idx, data):
+    if "nonlin"==type:
+      self._updateNodeData(self._cons_NL["All"], idx, data)
+    elif "lin"==type:
+      self._updateNodeData(self._cons_NL["All"], idx, data)
+    else:  # "logical"==type:
+      self._updateNodeData(self._cons_NL["All"], idx, data)
+
+  def UpdateFlatConGroup(self, type, data):
+    self._cons_Flat_Group[type] = data
+
+  def UpdateFlatCon(self, type, idx, data):
+    if type not in self._cons_Flat:
+      self._cons_Flat[type] = []
+    self._updateNodeData(self._cons_Flat[type], idx, data)
+
+  def _updateNodeData(self, specnodecnt, idx, data):
+    data1, upd = self._updateItemData(specnodecnt, idx, data)
+    if (not upd):
+      idx = self._graph.AddNode(data1)
+      data1["node_index"] = idx
+
+  def _updateItemData(self, specnodecnt, idx, data):
+    if len(specnodecnt)<=idx:
+      specnodecnt.insert(idx, {})
+    if (specnodecnt[idx] is None):    ## No such item
+      specnodecnt[idx] = {}
+    ifEmpty = 0==len(specnodecnt[idx])
+    self._updateMap(specnodecnt[idx], data)
+    return specnodecnt[idx], ifEmpty
+
+  def _updateMap(self, data1, data2):
+    data1.update(data2)
+
+  # Match keyword to the original model
+  def MatchOrigModel(self, keyw):
+    result = {}
+    result["NL Variables"] = self._matchRecords(self._vars, keyw, "is_from_nl")
+    result["NL Objectives"] = self._matchRecords(self._objs_NL, keyw)
+    result["NL Constraints"] \
+      = self._matchRecords(self._cons_NL.get("All"), keyw)
+    #result["NL Nonlinear Constraints"] \
+    #  = self._matchRecords(self._cons_NL.get("Nonlinear"), keyw)
+    #result["NL Linear Constraints"] \
+    #  = self._matchRecords(self._cons_NL.get("Linear"), keyw)
+    #result["NL Logical Constraints"] \
+    #  = self._matchRecords(self._cons_NL.get("Logical"), keyw)
+    #result["NL SOS Constraints"] \
+    #  = self._matchRecords(self._cons_NL.get("SOS"), keyw)
+    return result
+
+  # Match keyword to the final model
+  def MatchFinalModel(self, keyw):
+    result = {}
+    result["Variables"] = self._matchRecords(self._vars, keyw)
+    result["Objectives"] = self._matchRecords(self._objs, keyw)
+    for ct, cv in self._cons_Flat.items():
+      result["Constraints '" + ct + "'"] \
+        = self._matchRecords(self._cons_Flat[ct], keyw)
+    return result
+
+  # Add records containing keyword
+  # @return array of strings
+  def _matchRecords(self, cnt, keyw, keyNeed1=None):
+    result = ""
+    if cnt is None:
+      return result
+    for i in cnt:
+      pr = str(i)         ## TODO printed form
+      if "printed" in i:
+        pr = i["printed"]
+      if (""==keyw or keyw in pr) \
+      and (keyNeed1==None \
+        or (keyNeed1 in i and 1==i[keyNeed1])):
+        result = result + "\n\n" + pr        ## Markdown
+    return result
diff --git a/support/modelexplore/scripts/python/modelreader.py b/support/modelexplore/scripts/python/modelreader.py
new file mode 100644
index 000000000..4c7833d11
--- /dev/null
+++ b/support/modelexplore/scripts/python/modelreader.py
@@ -0,0 +1,48 @@
+# This Python file uses the following encoding: utf-8
+
+# if __name__ == "__main__":
+#     pass
+
+import streamlit as st
+
+import json
+from scripts.python.model import Model
+
+class ModelReader:
+  """
+  Model reader
+  """
+
+  def __init__(self):
+    self._model = Model()
+
+  def ReadModel(self, uploader):
+    for line in uploader:
+      # removing the new line characters
+      self._processLine(line.rstrip())
+    return self._model
+
+  # Process next line
+  def _processLine(self, line: str):
+    values = json.loads(line)
+    self._addDataChunk(values)
+
+  # Add data chunk as a JSON-like object
+  def _addDataChunk(self, chunk):
+    if "VAR_index" in chunk:
+      self._model.UpdateVar(chunk["VAR_index"], chunk)
+    elif "NL_OBJECTIVE_index" in chunk:
+      self._model.UpdateNLObj(chunk["NL_OBJECTIVE_index"], chunk)
+    elif "NL_CON_TYPE" in chunk:
+      self._model.UpdateNLCon(chunk["NL_CON_TYPE"], chunk["index"], chunk)
+    elif "OBJECTIVE_index" in chunk:
+      self._model.UpdateFlatObj(chunk["OBJECTIVE_index"], chunk)
+    elif "CON_GROUP" in chunk:
+        self._model.UpdateFlatConGroup(chunk["CON_TYPE"], chunk)
+    elif "CON_TYPE" in chunk:
+      self._model.UpdateFlatCon(chunk["CON_TYPE"], chunk["index"], chunk)
+
+
+def ReadExplorerModel(uploader):
+  mr = ModelReader()
+  return mr.ReadModel(uploader)
diff --git a/support/modelexplore/scripts/python/modelview.py b/support/modelexplore/scripts/python/modelview.py
new file mode 100644
index 000000000..626262dca
--- /dev/null
+++ b/support/modelexplore/scripts/python/modelview.py
@@ -0,0 +1,22 @@
+# This Python file uses the following encoding: utf-8
+
+# if __name__ == "__main__":
+#     pass
+
+class ModelView:
+  """
+  A view of a (sub) model
+  """
+
+  def __init__(self):
+    self._data = None
+
+    self._vars = {"Variables": []}
+    self._cons = {"Constraints": []}
+    self._objs = {"Objectives": []}
+
+  def SetData(self, data):
+    self._data = data
+
+  def GetData(self):
+    return self._data