diff --git a/new/feature.jam b/new/feature.jam
index f8c5e1ba9..11e46c1d3 100644
--- a/new/feature.jam
+++ b/new/feature.jam
@@ -31,8 +31,9 @@ import errors : error lol->list ;
 import sequence ;
 import regex ;
 import set ;
+import utility ;
 
-all-attributes =
+.all-attributes =
 
     implicit    # features whose values alone identify the
                 # feature. For example, a user is not required to
@@ -94,8 +95,8 @@ all-attributes =
 
   ;
 
-all-features = ;
-all-implicit-values = ;
+.all-features = ;
+.all-implicit-values = ;
 
 # Transform features by bracketing any elements which aren't already
 # bracketed by "<>"
@@ -115,12 +116,12 @@ rule feature ( name : values * : attributes * )
     local error ;
 
     # if there are any unknown attributes...
-    if ! ( $(attributes) in $(all-attributes) )
+    if ! ( $(attributes) in $(.all-attributes) )
     {
         error = unknown attributes:
-          [ set.difference $(attributes) : $(all-attributes) ] ;
+          [ set.difference $(attributes) : $(.all-attributes) ] ;
     }
-    else if $(name) in $(all-features)
+    else if $(name) in $(.all-features)
     {
         error = feature already defined: ;
     }
@@ -144,7 +145,7 @@ rule feature ( name : values * : attributes * )
     $(name).subfeatures ?= ;
     $(attributes).features += $(name) ;
 
-    all-features += $(name) ;
+    .all-features += $(name) ;
     extend $(name) : $(values) ;
 }
 
@@ -172,7 +173,7 @@ rule defaults ( features * )
 # returns true iff all elements of names are valid features.
 rule valid ( names + )
 {
-    if [ grist $(names) ] in $(all-features)
+    if [ grist $(names) ] in $(.all-features)
     {
         return true ;
     }
@@ -214,12 +215,9 @@ local rule find-implied-subfeature ( feature subvalue : value-string ? )
         error invalid feature $(feature) ;
     }
 
-    local v
-      = subfeature($(feature),$(subvalue))
-        subfeature($(feature),$(value-string),$(subvalue)) ;
+    value-string ?= "" ;
 
-    local subfeature = $($(v)) ;
-    return $(subfeature[1]) ;
+    return $($(feature)$(value-string)<>$(subvalue).subfeature) ;
 }
 
 # Given a feature name and a subfeature value, find the associated
@@ -242,7 +240,7 @@ rule implied-subfeature ( feature subvalue : value-string ? )
 # generate an error if the feature is unknown
 local rule validate-feature ( feature )
 {
-    if ! [ grist $(feature) ] in $(all-features)
+    if ! [ grist $(feature) ] in $(.all-features)
     {
         error unknown feature \"$(feature)\" ;
     }
@@ -266,7 +264,7 @@ local rule expand-subfeatures-aux ( feature ? : value )
     {
         feature = [ implied-feature $(components[1]) ] ;
     }
-    else if ! $(feature) in $(all-features)
+    else if ! $(feature) in $(.all-features)
     {
         error unknown feature $(feature) ;
     }
@@ -295,7 +293,7 @@ rule expand-subfeatures ( properties * )
     return $(result) ;
 }
 
-# Helper for extend, below. Handles the case feature case.
+# Helper for extend, below. Handles the feature case.
 local rule extend-feature ( feature : values * )
 {
     validate-feature $(feature) ;
@@ -310,12 +308,12 @@ local rule extend-feature ( feature : values * )
             $(v).implicit-feature = $(feature) ;
         }
 
-        all-implicit-values += $(values) ;
+        .all-implicit-values += $(values) ;
     }
     $(feature).values += $(values) ;
 }
 
-# Checks that value-string is a valide value-string for the given feature.
+# Checks that value-string is a valid value-string for the given feature.
 local rule validate-value-string ( feature value-string )
 {
     local values = $(value-string) ;
@@ -354,12 +352,12 @@ rule extend-subfeature ( feature value-string ? : subfeature : subvalues * )
         validate-value-string $(feature) $(value-string) ;
     }
 
+    # provide a way to get from the given feature or property and
+    # subfeature value to the subfeature name.
+    value-string ?= "" ;
     for local subvalue in $(subvalues)
     {
-        local v
-          = subfeature($(feature),$(value-string),$(subvalue))
-            subfeature($(feature),$(subvalue)) ;
-        $(v[1]) = $(subfeature) ;
+        $(feature)$(value-string)<>$(subvalue).subfeature = $(subfeature) ;
     }
 }
 
@@ -431,6 +429,8 @@ rule subfeature ( feature value-string ? : subfeature : subvalues * )
     }
     $(feature).subfeatures += $(subfeature) ;
     extend-subfeature $(feature) $(value-string) : $(subfeature) : $(subvalues) ;
+    local f = [ utility.ungrist $(feature) ] ;
+    feature $(f)-$(subfeature) : $(subvalues) ;
 }
 
 # Set the components of the given composite property
@@ -449,6 +449,10 @@ rule compose ( composite-property : component-properties * )
                 $($(composite-property).components) ;
     }
 
+    if $(composite-property) in $(components)
+    {
+        errror composite property "$(composite-property)" cannot have itself as a component ;
+    }
     $(composite-property).components = $(component-properties) ;
 }
 
@@ -486,6 +490,8 @@ rule free-features ( )
     return $(free.features) ;
 }
 
+# Expand all composite properties in the set so that all components
+# are explicitly expressed.
 rule expand-composites ( properties * )
 {
     local explicit-features = $(properties:G) ;
@@ -538,6 +544,76 @@ rule expand ( properties * )
     return [ expand-composites $(expanded) ] ;
 }
 
+
+# Helper rule for minimize, below - return true iff property's feature
+# is present in the contents of the variable named by feature-set-var.
+local rule in-features ( feature-set-var property )
+{
+    if $(property:G) in $($(feature-set-var))
+    {
+        return true ;
+    }
+}
+
+# Given an expanded property set, eliminate all redundancy: properties
+# which are elements of other (composite) properties in the set will
+# be eliminated, implicit properties will be expressed without feature
+# grist, and sub-property values will be expressed as elements joined
+# to the corresponding main property.
+rule minimize ( properties * )
+{
+    # remove properties implied by composite features
+    local x = $(properties) ;
+    for local p in $(properties)
+    {
+        if ! $(p:G)
+        {
+            error minimize requires an expanded property set, but \"$(p)\"
+              appears to be an un-expanded implicit feature ;
+        }
+        x = [ set.difference $(x) : $($(p).components) ] ;
+    }
+    
+    # handle subfeatures and implicit features
+    local result ;
+    while $(x)
+    {
+        local p = $(x[1]) ;
+        local f = $(p:G) ;
+        
+        # eliminate features in implicit properties.
+        if implicit in [ attributes $(f) ]
+        {
+            p = $(p:G="") ;
+        }
+        
+        # locate all subproperties of f in the property set
+        local subproperties ;
+        local subfeatures = $($(f).subfeatures) ;
+        if $(subfeatures)
+        {
+            local f_ = [ utility.ungrist $(f) ] ;
+            subfeatures = [ grist $(f_)-$(subfeatures) ] ;
+            subproperties = [ sequence.filter in-features subfeatures : $(x) ] ;
+        }
+        
+        if $(subproperties)
+        {
+            # reconstitute the joined property name
+            local sorted = [ sequence.insertion-sort $(subproperties) ] ;
+            result += $(p)-$(sorted:G="":J=-) ;
+              
+            x = [ set.difference $(x[2-]) : $(subproperties) ] ;
+        }
+        else
+        {
+            result += $(p) ;
+            x = $(x[2-]) ;
+        }
+    }
+    return $(result) ;
+}
+
 # Given a property-set of the form
 #       v1/v2/...vN-1/<fN>vN/<fN+1>vN+1/...<fM>vM
 #
@@ -619,6 +695,18 @@ local rule __test__ ( )
           : expand debug <optimization>on
           ;
 
+        assert.result gcc-3.0.1 debug <optimization>on
+          : minimize [ expand gcc-3.0.1 debug <optimization>on ]
+          ;
+        
+        assert.result gcc-3.0.1 debug
+          : minimize [ expand gcc-3.0.1 debug <optimization>off ]
+          ;
+        
+        assert.result debug <optimization>on
+          : minimize [ expand debug <optimization>on ]
+          ;
+        
         assert.result <x>y/z <a>b/c <d>e/f
           : split <x>y/z/<a>b/c/<d>e/f
           ;
diff --git a/new/property.jam b/new/property.jam
index 0ca53dcf9..05e738d13 100644
--- a/new/property.jam
+++ b/new/property.jam
@@ -77,16 +77,57 @@ rule refine ( properties * : requirements * : feature-space ? )
     }
 }
 
-# Returns a path which represents the given property set.
-# TODO: this is a quick sketch. We need much better logic.
-rule as-path ( properties * )
+# Helper for as-path, below. Orders properties with the implicit ones
+# first, and within the two sections in alphabetical order of feature
+# name.
+local rule path-order ( feature-space x y )
 {
+    if $(y:G) && ! $(x:G)
+    {
+        return true ;
+    }
+    else if $(x:G) && ! $(y:G)
+    {
+        return ;
+    }
+    else
+    {
+        if ! $(x:G)
+        {
+            x = [ $(feature-space).expand-subfeatures $(x) ] ;
+            y = [ $(feature-space).expand-subfeatures $(y) ] ;
+        }
+        
+        if $(x[0]) < $(y[0])
+        {
+            return true ;
+        }
+    }
+}
+
+# Returns a path which represents the given expanded property set.
+rule as-path ( properties * : feature-space ? )
+{
+    feature-space ?= feature ;
+    
+    # trim redundancy
+    properties = [ $(feature-space).minimize $(properties) ] ;
+    
+    # sort according to path-order
+    properties = [ sequence.insertion-sort $(properties) : path-order $(feature-space) ] ;
+    
     local components ;
     for local p in $(properties)
     {
-        local name = [ ungrist $(p:G) ] ;
-        local value = $(p:G=) ;
-        components += $(name)-$(value) ;
+        if $(p:G)
+        {
+            local f = [ ungrist $(p:G) ] ;
+            components += $(f)-$(p:G=) ;
+        }
+        else
+        {
+            components += $(p) ;
+        }
     }
     return $(components:J=/) ;
 }
@@ -111,6 +152,7 @@ local rule __test__ ( )
 
         compose <variant>debug : <define>_DEBUG <optimization>off ;
         compose <variant>release : <define>NDEBUG <optimization>on ;
+
     }
 
     assert.result <toolset>gcc <rtti>off <define>FOO
@@ -129,15 +171,20 @@ local rule __test__ ( )
         : refine <toolset>gcc : <rtti>off : $(test-space)
         ;
 
+    assert.result debug
+      : as-path <optimization>off <variant>debug
+      : $(test-space)
+      ;
+
+    assert.result gcc/debug/rtti-off
+      : as-path <toolset>gcc <optimization>off <rtti>off <variant>debug
+      : $(test-space)
+      ;
 
     r = [ refine <toolset>gcc <rtti>off
             : <rtti>on
             : $(test-space) ] ;
     assert.equal $(r[1]) : "@error" ;
 
-    assert.result optimization-off/variant-debug
-        : as-path <optimization>off <variant>debug
-        ;
-
 }
 
diff --git a/test/project_test3.py b/test/project_test3.py
index 83f296bb2..ed8b94515 100644
--- a/test/project_test3.py
+++ b/test/project_test3.py
@@ -11,14 +11,21 @@ t.set_tree("project-test3")
 t.run_build_system()
 
 t.expect_addition("bin/a.obj")
-t.fail_test(t.read("bin/a.obj") != \
-"""variant-debug/optimization-off
+
+expected = """debug
 a.cpp
-""")
+"""
+
+if t.read("bin/a.obj") != expected:
+    print '***expected:'
+    print expected
+    print '***got this instead:'
+    print t.read("bin/a.obj")
+    t.fail_test(1)
 
 t.expect_addition("bin/a.exe")
-t.fail_test(t.read("bin/a.exe") != \
-"""variant-debug/optimization-off
+t.fail_test(t.read("bin/a.exe") !=
+"""debug
 bin/a.obj
 """)
 
diff --git a/v2/build/feature.jam b/v2/build/feature.jam
index f8c5e1ba9..11e46c1d3 100644
--- a/v2/build/feature.jam
+++ b/v2/build/feature.jam
@@ -31,8 +31,9 @@ import errors : error lol->list ;
 import sequence ;
 import regex ;
 import set ;
+import utility ;
 
-all-attributes =
+.all-attributes =
 
     implicit    # features whose values alone identify the
                 # feature. For example, a user is not required to
@@ -94,8 +95,8 @@ all-attributes =
 
   ;
 
-all-features = ;
-all-implicit-values = ;
+.all-features = ;
+.all-implicit-values = ;
 
 # Transform features by bracketing any elements which aren't already
 # bracketed by "<>"
@@ -115,12 +116,12 @@ rule feature ( name : values * : attributes * )
     local error ;
 
     # if there are any unknown attributes...
-    if ! ( $(attributes) in $(all-attributes) )
+    if ! ( $(attributes) in $(.all-attributes) )
     {
         error = unknown attributes:
-          [ set.difference $(attributes) : $(all-attributes) ] ;
+          [ set.difference $(attributes) : $(.all-attributes) ] ;
     }
-    else if $(name) in $(all-features)
+    else if $(name) in $(.all-features)
     {
         error = feature already defined: ;
     }
@@ -144,7 +145,7 @@ rule feature ( name : values * : attributes * )
     $(name).subfeatures ?= ;
     $(attributes).features += $(name) ;
 
-    all-features += $(name) ;
+    .all-features += $(name) ;
     extend $(name) : $(values) ;
 }
 
@@ -172,7 +173,7 @@ rule defaults ( features * )
 # returns true iff all elements of names are valid features.
 rule valid ( names + )
 {
-    if [ grist $(names) ] in $(all-features)
+    if [ grist $(names) ] in $(.all-features)
     {
         return true ;
     }
@@ -214,12 +215,9 @@ local rule find-implied-subfeature ( feature subvalue : value-string ? )
         error invalid feature $(feature) ;
     }
 
-    local v
-      = subfeature($(feature),$(subvalue))
-        subfeature($(feature),$(value-string),$(subvalue)) ;
+    value-string ?= "" ;
 
-    local subfeature = $($(v)) ;
-    return $(subfeature[1]) ;
+    return $($(feature)$(value-string)<>$(subvalue).subfeature) ;
 }
 
 # Given a feature name and a subfeature value, find the associated
@@ -242,7 +240,7 @@ rule implied-subfeature ( feature subvalue : value-string ? )
 # generate an error if the feature is unknown
 local rule validate-feature ( feature )
 {
-    if ! [ grist $(feature) ] in $(all-features)
+    if ! [ grist $(feature) ] in $(.all-features)
     {
         error unknown feature \"$(feature)\" ;
     }
@@ -266,7 +264,7 @@ local rule expand-subfeatures-aux ( feature ? : value )
     {
         feature = [ implied-feature $(components[1]) ] ;
     }
-    else if ! $(feature) in $(all-features)
+    else if ! $(feature) in $(.all-features)
     {
         error unknown feature $(feature) ;
     }
@@ -295,7 +293,7 @@ rule expand-subfeatures ( properties * )
     return $(result) ;
 }
 
-# Helper for extend, below. Handles the case feature case.
+# Helper for extend, below. Handles the feature case.
 local rule extend-feature ( feature : values * )
 {
     validate-feature $(feature) ;
@@ -310,12 +308,12 @@ local rule extend-feature ( feature : values * )
             $(v).implicit-feature = $(feature) ;
         }
 
-        all-implicit-values += $(values) ;
+        .all-implicit-values += $(values) ;
     }
     $(feature).values += $(values) ;
 }
 
-# Checks that value-string is a valide value-string for the given feature.
+# Checks that value-string is a valid value-string for the given feature.
 local rule validate-value-string ( feature value-string )
 {
     local values = $(value-string) ;
@@ -354,12 +352,12 @@ rule extend-subfeature ( feature value-string ? : subfeature : subvalues * )
         validate-value-string $(feature) $(value-string) ;
     }
 
+    # provide a way to get from the given feature or property and
+    # subfeature value to the subfeature name.
+    value-string ?= "" ;
     for local subvalue in $(subvalues)
     {
-        local v
-          = subfeature($(feature),$(value-string),$(subvalue))
-            subfeature($(feature),$(subvalue)) ;
-        $(v[1]) = $(subfeature) ;
+        $(feature)$(value-string)<>$(subvalue).subfeature = $(subfeature) ;
     }
 }
 
@@ -431,6 +429,8 @@ rule subfeature ( feature value-string ? : subfeature : subvalues * )
     }
     $(feature).subfeatures += $(subfeature) ;
     extend-subfeature $(feature) $(value-string) : $(subfeature) : $(subvalues) ;
+    local f = [ utility.ungrist $(feature) ] ;
+    feature $(f)-$(subfeature) : $(subvalues) ;
 }
 
 # Set the components of the given composite property
@@ -449,6 +449,10 @@ rule compose ( composite-property : component-properties * )
                 $($(composite-property).components) ;
     }
 
+    if $(composite-property) in $(components)
+    {
+        errror composite property "$(composite-property)" cannot have itself as a component ;
+    }
     $(composite-property).components = $(component-properties) ;
 }
 
@@ -486,6 +490,8 @@ rule free-features ( )
     return $(free.features) ;
 }
 
+# Expand all composite properties in the set so that all components
+# are explicitly expressed.
 rule expand-composites ( properties * )
 {
     local explicit-features = $(properties:G) ;
@@ -538,6 +544,76 @@ rule expand ( properties * )
     return [ expand-composites $(expanded) ] ;
 }
 
+
+# Helper rule for minimize, below - return true iff property's feature
+# is present in the contents of the variable named by feature-set-var.
+local rule in-features ( feature-set-var property )
+{
+    if $(property:G) in $($(feature-set-var))
+    {
+        return true ;
+    }
+}
+
+# Given an expanded property set, eliminate all redundancy: properties
+# which are elements of other (composite) properties in the set will
+# be eliminated, implicit properties will be expressed without feature
+# grist, and sub-property values will be expressed as elements joined
+# to the corresponding main property.
+rule minimize ( properties * )
+{
+    # remove properties implied by composite features
+    local x = $(properties) ;
+    for local p in $(properties)
+    {
+        if ! $(p:G)
+        {
+            error minimize requires an expanded property set, but \"$(p)\"
+              appears to be an un-expanded implicit feature ;
+        }
+        x = [ set.difference $(x) : $($(p).components) ] ;
+    }
+    
+    # handle subfeatures and implicit features
+    local result ;
+    while $(x)
+    {
+        local p = $(x[1]) ;
+        local f = $(p:G) ;
+        
+        # eliminate features in implicit properties.
+        if implicit in [ attributes $(f) ]
+        {
+            p = $(p:G="") ;
+        }
+        
+        # locate all subproperties of f in the property set
+        local subproperties ;
+        local subfeatures = $($(f).subfeatures) ;
+        if $(subfeatures)
+        {
+            local f_ = [ utility.ungrist $(f) ] ;
+            subfeatures = [ grist $(f_)-$(subfeatures) ] ;
+            subproperties = [ sequence.filter in-features subfeatures : $(x) ] ;
+        }
+        
+        if $(subproperties)
+        {
+            # reconstitute the joined property name
+            local sorted = [ sequence.insertion-sort $(subproperties) ] ;
+            result += $(p)-$(sorted:G="":J=-) ;
+              
+            x = [ set.difference $(x[2-]) : $(subproperties) ] ;
+        }
+        else
+        {
+            result += $(p) ;
+            x = $(x[2-]) ;
+        }
+    }
+    return $(result) ;
+}
+
 # Given a property-set of the form
 #       v1/v2/...vN-1/<fN>vN/<fN+1>vN+1/...<fM>vM
 #
@@ -619,6 +695,18 @@ local rule __test__ ( )
           : expand debug <optimization>on
           ;
 
+        assert.result gcc-3.0.1 debug <optimization>on
+          : minimize [ expand gcc-3.0.1 debug <optimization>on ]
+          ;
+        
+        assert.result gcc-3.0.1 debug
+          : minimize [ expand gcc-3.0.1 debug <optimization>off ]
+          ;
+        
+        assert.result debug <optimization>on
+          : minimize [ expand debug <optimization>on ]
+          ;
+        
         assert.result <x>y/z <a>b/c <d>e/f
           : split <x>y/z/<a>b/c/<d>e/f
           ;
diff --git a/v2/build/property.jam b/v2/build/property.jam
index 0ca53dcf9..05e738d13 100644
--- a/v2/build/property.jam
+++ b/v2/build/property.jam
@@ -77,16 +77,57 @@ rule refine ( properties * : requirements * : feature-space ? )
     }
 }
 
-# Returns a path which represents the given property set.
-# TODO: this is a quick sketch. We need much better logic.
-rule as-path ( properties * )
+# Helper for as-path, below. Orders properties with the implicit ones
+# first, and within the two sections in alphabetical order of feature
+# name.
+local rule path-order ( feature-space x y )
 {
+    if $(y:G) && ! $(x:G)
+    {
+        return true ;
+    }
+    else if $(x:G) && ! $(y:G)
+    {
+        return ;
+    }
+    else
+    {
+        if ! $(x:G)
+        {
+            x = [ $(feature-space).expand-subfeatures $(x) ] ;
+            y = [ $(feature-space).expand-subfeatures $(y) ] ;
+        }
+        
+        if $(x[0]) < $(y[0])
+        {
+            return true ;
+        }
+    }
+}
+
+# Returns a path which represents the given expanded property set.
+rule as-path ( properties * : feature-space ? )
+{
+    feature-space ?= feature ;
+    
+    # trim redundancy
+    properties = [ $(feature-space).minimize $(properties) ] ;
+    
+    # sort according to path-order
+    properties = [ sequence.insertion-sort $(properties) : path-order $(feature-space) ] ;
+    
     local components ;
     for local p in $(properties)
     {
-        local name = [ ungrist $(p:G) ] ;
-        local value = $(p:G=) ;
-        components += $(name)-$(value) ;
+        if $(p:G)
+        {
+            local f = [ ungrist $(p:G) ] ;
+            components += $(f)-$(p:G=) ;
+        }
+        else
+        {
+            components += $(p) ;
+        }
     }
     return $(components:J=/) ;
 }
@@ -111,6 +152,7 @@ local rule __test__ ( )
 
         compose <variant>debug : <define>_DEBUG <optimization>off ;
         compose <variant>release : <define>NDEBUG <optimization>on ;
+
     }
 
     assert.result <toolset>gcc <rtti>off <define>FOO
@@ -129,15 +171,20 @@ local rule __test__ ( )
         : refine <toolset>gcc : <rtti>off : $(test-space)
         ;
 
+    assert.result debug
+      : as-path <optimization>off <variant>debug
+      : $(test-space)
+      ;
+
+    assert.result gcc/debug/rtti-off
+      : as-path <toolset>gcc <optimization>off <rtti>off <variant>debug
+      : $(test-space)
+      ;
 
     r = [ refine <toolset>gcc <rtti>off
             : <rtti>on
             : $(test-space) ] ;
     assert.equal $(r[1]) : "@error" ;
 
-    assert.result optimization-off/variant-debug
-        : as-path <optimization>off <variant>debug
-        ;
-
 }
 
diff --git a/v2/test/project_test3.py b/v2/test/project_test3.py
index 83f296bb2..ed8b94515 100644
--- a/v2/test/project_test3.py
+++ b/v2/test/project_test3.py
@@ -11,14 +11,21 @@ t.set_tree("project-test3")
 t.run_build_system()
 
 t.expect_addition("bin/a.obj")
-t.fail_test(t.read("bin/a.obj") != \
-"""variant-debug/optimization-off
+
+expected = """debug
 a.cpp
-""")
+"""
+
+if t.read("bin/a.obj") != expected:
+    print '***expected:'
+    print expected
+    print '***got this instead:'
+    print t.read("bin/a.obj")
+    t.fail_test(1)
 
 t.expect_addition("bin/a.exe")
-t.fail_test(t.read("bin/a.exe") != \
-"""variant-debug/optimization-off
+t.fail_test(t.read("bin/a.exe") !=
+"""debug
 bin/a.obj
 """)