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  • Top File of PVS digraphs Library

     
    %  min_walk_reduced      -- theorem that minimum walk is reduced
    %  min_walks             -- minimum walk satisfying a propertyx
    %  path_ops              -- deleting vertex and edge operations
    %  paths                 -- fundamental definition and properties about paths
    %  reduce_walks          -- operation to reduce a walk
    %  sep_sets              -- definition of separating sets
    %  di_subgraphs           -- generation of di_subgraphs from vertex sets
    %  di_subgraphs_from_walk -- generation of di_subgraphs from walks
    %  subtrees              -- subtrees of a digraph
    %  trees                 -- fundamental definition of trees
    %  walk_inductions       -- induction on length of a walk
    %  walks                 -- fundamental definition and properties of walks
    %
    %------------------------------------------------------------------------------
    top: THEORY
    
    BEGIN
    
       IMPORTING digraphs,
                 digraph_deg, 
                 walks,
                 paths, 
                 path_ops,
                 dags,
                 circuits, 
                 cycles, 
                 di_subgraphs, 
                 di_subgraphs_from_walk, 
                 digraph_ops,
                 max_di_subgraphs,
                 max_subtrees,
                 trees, 
                 subtrees, 
                 walk_inductions,
                 min_walk_reduced, 
                 reduce_walks,
    	     abstract_min,
    	     abstract_max,
    	     pairs,
    	     digraph_conn_defs,
    	     digraph_inductions,
    	     ind_paths,
    	     min_walks,         
    	     sep_sets,
    	     weighted_digraphs,
                 wgt_digraphs_props,
                 Eulerian
    
    %  digraph_deg_sum       -- theorem relating vertex degree and number of edges
    %  tree_circ             -- theorem that tree has no circuits
    %  digraph_connected     -- all connected defs are equivalent
    %  ramsey_new            -- Ramsey's theorem
    %  menger                -- menger's theorem
    %  tree_paths            -- theorem that tree has only one path between vertices
    %  circuit_deg           -- degree of circuits
    %  cycle_deg             -- theorem about degree and existence of cycle
    %  digraph_complected    -- unusual definition of connected digraph
    %  digraph_conn_piece    -- structural connected ==> piece connected
    %  digraph_path_conn     -- path connected ==> structural connected
    %  digraph_piece_path    -- piece connected ==> path connected
    %  h_menger              -- hard menger 
    %  meng_scaff            -- scaffolding for hard menger proof
    %  meng_scaff_defs       -- scaffolding for hard menger proof
    %  meng_scaff_prelude    -- scaffolding for hard menger proof
    %  sep_set_lems          -- properties of separating sets
    
    %            digraph_deg_sum, 
    %            tree_circ, 
    %            digraph_connected, 
    %            ramsey_new,
    %            menger, 
    %            tree_paths,         % Proof incorrect
    %            circuit_deg,  
    %	     cycle_deg,          % not attempted yet
    %	     digraph_complected  ,
    %	     digraph_conn_piece  ,
    %	     digraph_connected   ,
    %	     digraph_path_conn   ,
    %	     digraph_piece_path  ,
    %	     h_menger          ,
    %	     meng_scaff        ,
    %	     meng_scaff_defs   ,
    %	     meng_scaff_prelude,
    %	     menger            ,
    %	     sep_set_lems      ,
    
    
    END top
    
    
    
    

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