Proof Trace Export for step_neg/inv3/INV (true) from
GetPositiveElements/GetPositiveElements.pl

Proof Steps
1. reselect_hyp (pos ⊆ ELEMENTS)
2. reselect_hyp (elements ⊆ ELEMENTS)
3. reselect_hyp (ELEMENTS ⊂ ℤ)
4. reselect_hyp (pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x})
5. reselect_hyp (finite(ELEMENTS))
6. imp_r
7. imp_case (elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x})
8. hyp
9. eq (lr,pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x})
10. DERIV_EQUAL ({x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} = {x·0 < x ∧ x ∈ ELEMENTS∣x})
11. DEF_SUBSETEQ ({x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS)
12. DEF_SUBSETEQ ({x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ {x·0 < x ∧ x ∈ ELEMENTS∣x})
13. all_r
14. imp_r
15. SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x})
16. SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x})
17. hyp
18. DEF_IN_SETMINUS (y ∈ ELEMENTS ∖ elements)
19. hyp
20. DEF_SUBSETEQ ({x·0 < x ∧ x ∈ ELEMENTS∣x} ⊆ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x})
21. all_r
22. imp_r
23. SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x})
24. SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x})
25. hyp
26. SIMP_SETMINUS_EQUAL_EMPTY (elements ∖ {e} = ∅)
27. DEF_SUBSETEQ (elements ⊆ {e})
28. ∀ instantiation in hyp 6 for ID x: 'y'
29. true_goal
30. imp_case (y ∈ elements ⇒ y ∈ {e})
31. DEF_IN_SETMINUS (y ∈ ELEMENTS ∖ elements)
32. hyp
33. hyp
34. DEF_IN_SETMINUS (y ∈ ELEMENTS ∖ elements)
35. hyp
36. and_l (e ≤ 0 ∧ e ∈ elements)
37. SIMP_IN_SING (y ∈ {e})
38. eq (rl,y = e)
39. cntr

ProB Version: 1.16.0-nightly (25fadf907101913f4f3f41a98fdcdc96920fbb46)
Generated on 26/01/2026 at 12:50
 
Proof Tree
prob_graph dot_node_0 Select PO dot_node_10 e ≤ 0 ∧ e ∈ elements elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} elements ∖ {e} = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_0->dot_node_10 step_neg/inv3/INV (true) dot_node_1 Proven. dot_node_2 Proven. dot_node_3 Proven. dot_node_4 Proven. dot_node_5 Proven. dot_node_6 Proven. dot_node_7 Proven. dot_node_8 Proven. dot_node_9 Proven. dot_node_11 e ≤ 0 ∧ e ∈ elements elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} pos ⊆ ELEMENTS elements ∖ {e} = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_10->dot_node_11 reselect_hyp (pos ⊆ ELEMENTS) dot_node_12 e ≤ 0 ∧ e ∈ elements elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} pos ⊆ ELEMENTS elements ⊆ ELEMENTS elements ∖ {e} = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_11->dot_node_12 reselect_hyp (elements ⊆ ELEMENTS) dot_node_13 e ≤ 0 ∧ e ∈ elements elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} pos ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ elements ∖ {e} = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_12->dot_node_13 reselect_hyp (ELEMENTS ⊂ ℤ) dot_node_14 e ≤ 0 ∧ e ∈ elements elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} pos ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} elements ∖ {e} = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_13->dot_node_14 reselect_hyp (pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x}) dot_node_15 e ≤ 0 ∧ e ∈ elements elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} pos ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} finite(ELEMENTS) elements ∖ {e} = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_14->dot_node_15 reselect_hyp (finite(ELEMENTS)) dot_node_16 e ≤ 0 ∧ e ∈ elements elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} pos ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} finite(ELEMENTS) elements ∖ {e} = ∅ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_15->dot_node_16 imp_r dot_node_17 e ≤ 0 ∧ e ∈ elements pos ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_16->dot_node_17 imp_case (elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x}) dot_node_18 e ≤ 0 ∧ e ∈ elements pos ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} finite(ELEMENTS) elements ∖ {e} = ∅ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} pos = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_16->dot_node_18 imp_case (elements = ∅ ⇒ pos = {x·0 < x ∧ x ∈ ELEMENTS∣x}) dot_node_19 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} = {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_17->dot_node_19 eq (lr,pos = {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x}) dot_node_18->dot_node_1 hyp dot_node_20 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_19->dot_node_20 DERIV_EQUAL ({x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} = {x·0 < x ∧ x ∈ ELEMENTS∣x}) dot_node_21 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) {x·0 < x ∧ x ∈ ELEMENTS∣x} ⊆ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} dot_node_19->dot_node_21 DERIV_EQUAL ({x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} = {x·0 < x ∧ x ∈ ELEMENTS∣x}) dot_node_22 e ≤ 0 ∧ e ∈ elements (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ ELEMENTS)) elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_20->dot_node_22 DEF_SUBSETEQ ({x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS) dot_node_30 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x} ⇒ y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x})) dot_node_21->dot_node_30 DEF_SUBSETEQ ({x·0 < x ∧ x ∈ ELEMENTS∣x} ⊆ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x}) dot_node_23 e ≤ 0 ∧ e ∈ elements (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ ELEMENTS)) elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x})) dot_node_22->dot_node_23 DEF_SUBSETEQ ({x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ {x·0 < x ∧ x ∈ ELEMENTS∣x}) dot_node_24 e ≤ 0 ∧ e ∈ elements (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ ELEMENTS)) elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_23->dot_node_24 all_r dot_node_25 e ≤ 0 ∧ e ∈ elements (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ ELEMENTS)) elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_24->dot_node_25 imp_r dot_node_26 e ≤ 0 ∧ e ∈ elements (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ ELEMENTS)) elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) 0 < y y ∈ ELEMENTS ∖ elements y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x} dot_node_25->dot_node_26 SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x}) dot_node_27 e ≤ 0 ∧ e ∈ elements (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ ELEMENTS)) elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) 0 < y y ∈ ELEMENTS ∖ elements 0 < y dot_node_26->dot_node_27 SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x}) dot_node_28 e ≤ 0 ∧ e ∈ elements (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ ELEMENTS)) elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) 0 < y y ∈ ELEMENTS ∖ elements y ∈ ELEMENTS dot_node_26->dot_node_28 SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x}) dot_node_27->dot_node_2 hyp dot_node_29 e ≤ 0 ∧ e ∈ elements (∀y·(y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⇒ y ∈ ELEMENTS)) elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) 0 < y y ∈ ELEMENTS ¬(y ∈ elements) y ∈ ELEMENTS dot_node_28->dot_node_29 DEF_IN_SETMINUS (y ∈ ELEMENTS ∖ elements) dot_node_29->dot_node_3 hyp dot_node_31 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x} ⇒ y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} dot_node_30->dot_node_31 all_r dot_node_32 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x} y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} dot_node_31->dot_node_32 imp_r dot_node_33 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} dot_node_32->dot_node_33 SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS∣x}) dot_node_34 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) 0 < y y ∈ ELEMENTS 0 < y dot_node_33->dot_node_34 SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x}) dot_node_35 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ∖ {e} = ∅ ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ ELEMENTS ∖ elements dot_node_33->dot_node_35 SIMP_IN_COMPSET_ONEPOINT (y ∈ {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x}) dot_node_34->dot_node_4 hyp dot_node_36 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) elements ⊆ {e} ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ ELEMENTS ∖ elements dot_node_35->dot_node_36 SIMP_SETMINUS_EQUAL_EMPTY (elements ∖ {e} = ∅) dot_node_37 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) (∀x·(x ∈ elements ⇒ x ∈ {e})) ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ ELEMENTS ∖ elements dot_node_36->dot_node_37 DEF_SUBSETEQ (elements ⊆ {e}) dot_node_38 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) (∀x·(x ∈ elements ⇒ x ∈ {e})) ¬(elements = ∅) 0 < y y ∈ ELEMENTS dot_node_37->dot_node_38 ∀ instantiation in hyp 6 for ID x: 'y' dot_node_39 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) y ∈ elements ⇒ y ∈ {e} ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ ELEMENTS ∖ elements dot_node_37->dot_node_39 ∀ instantiation in hyp 6 for ID x: 'y' dot_node_38->dot_node_5 true_goal dot_node_40 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS ¬(y ∈ elements) y ∈ ELEMENTS ∖ elements dot_node_39->dot_node_40 imp_case (y ∈ elements ⇒ y ∈ {e}) dot_node_41 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ {e} y ∈ ELEMENTS ∖ elements dot_node_39->dot_node_41 imp_case (y ∈ elements ⇒ y ∈ {e}) dot_node_42 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS ¬(y ∈ elements) y ∈ ELEMENTS dot_node_40->dot_node_42 DEF_IN_SETMINUS (y ∈ ELEMENTS ∖ elements) dot_node_43 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS ¬(y ∈ elements) ¬(y ∈ elements) dot_node_40->dot_node_43 DEF_IN_SETMINUS (y ∈ ELEMENTS ∖ elements) dot_node_44 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ {e} y ∈ ELEMENTS dot_node_41->dot_node_44 DEF_IN_SETMINUS (y ∈ ELEMENTS ∖ elements) dot_node_45 e ≤ 0 ∧ e ∈ elements {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ {e} ¬(y ∈ elements) dot_node_41->dot_node_45 DEF_IN_SETMINUS (y ∈ ELEMENTS ∖ elements) dot_node_42->dot_node_6 hyp dot_node_43->dot_node_7 hyp dot_node_44->dot_node_8 hyp dot_node_46 {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ∈ {e} e ≤ 0 e ∈ elements ¬(y ∈ elements) dot_node_45->dot_node_46 and_l (e ≤ 0 ∧ e ∈ elements) dot_node_47 {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS y = e e ≤ 0 e ∈ elements ¬(y ∈ elements) dot_node_46->dot_node_47 SIMP_IN_SING (y ∈ {e}) dot_node_48 {x·0 < x ∧ x ∈ ELEMENTS ∖ elements∣x} ⊆ ELEMENTS elements ⊆ ELEMENTS ELEMENTS ⊂ ℤ finite(ELEMENTS) ¬(elements = ∅) 0 < y y ∈ ELEMENTS y ≤ 0 y ∈ elements ¬(y ∈ elements) dot_node_47->dot_node_48 eq (rl,y = e) dot_node_48->dot_node_9 cntr