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; Adding Atoms to the Knowledge Base
;;;;;;;;;;;;;;;;;;;;;;
!(bind! &kb0 (new-space))
!(add-atom &kb0 (S a))
!(add-atom &kb0 (S b))
;MeTTaLog Only: !(assertEqual (atom-count &kb0) 2)
!(assertEqualToResult (get-atoms &kb0) ((S a) (S b)))

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; Removing Atoms from the Knowledge Base
;;;;;;;;;;;;;;;;;;;;;;
!(bind! &kb1 (new-space))
!(add-atom &kb1 (S a))
!(add-atom &kb1 (S b))
!(add-atom &kb1 (S c))
;; Remove an atom and test for success
!(assertTrue (remove-atom &kb1 (S b))) ; remove_atom on a present atom should return true
;; Attempt to remove a non-existent atom and test for failure
!(assertFalse (remove-atom &kb1 (S bogus))) ; remove_atom on a missing atom should return false
;; Verify the current state of the knowledge base
!(assertEqualToResult (get-atoms &kb1) ((S a) (S c)))

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; Replacing Atoms in the Knowledge Base
;;;;;;;;;;;;;;;;;;;;;;
!(bind! &kb2 (new-space))
(= (replace-atom $space $before $after) (if (remove-atom $space $before) (add-atom $space $after) False))
!(add-atom &kb2 (S a))
!(add-atom &kb2 (S b))
!(add-atom &kb2 (S c))
;; Replace an atom and verify the operation was successful
!(assertTrue (replace-atom &kb2 (S b) (S d)))
;; Check the new set of atoms in the knowledge base
!(assertEqualToResult (get-atoms &kb2) ((S a) (S d) (S c)))

;;;;;;;;;;;;;;;;;;;;;;
; Querying Atoms in the Knowledge Base
;;;;;;;;;;;;;;;;;;;;;;
!(bind! &kb3 (new-space))
!(add-atom &kb3 (E (S A) (S B)))
!(add-atom &kb3 (E (S C) (S D)))
;; Adding a duplicate pattern for testing multiple matches
!(add-atom &kb3 (E (S A) (S E)))
;; Verify that the query returns the expected matches
!(assertEqualToResult (match &kb3 (E (S A) $XX) $XX) ((S B) (S E)))

;;;;;;;;;;;;;;;;;;;;;;
; Comprehensive Test with Add, Remove, Query
;;;;;;;;;;;;;;;;;;;;;;
!(bind! &kb4 (new-space))
!(add-atom &kb4 (S initial-state))
;; Perform a sequence of operations
!(add-atom &kb4 (S x))
!(remove-atom &kb4 (S initial-state))
!(add-atom &kb4 (S y))
;; Final state should have x and y only
!(assertEqualToResult (get-atoms &kb4) ((S x) (S y)))
;; Query to test the presence of x and y
!(assertTrue (query &kb4 (S x)))
!(assertTrue (query &kb4 (S y)))