Database SUPPLEMENTARY MATERIAL (USERS' MATHBOXES) Mathbox for Glauco Siliprandi Real intervals iocleubd  
				
		 
		
			
		 
		Description:   An element of a left-open right-closed interval is smaller than or equal
       to its upper bound.  (Contributed by Glauco Siliprandi , 23-Oct-2021) 
		
			
				
					Ref 
					Expression 
				 
					
						Hypotheses 
						iocleubd.1    ⊢   φ   →   A  ∈    ℝ   *           
					 
					
						iocleubd.2    ⊢   φ   →   B  ∈    ℝ   *           
					 
					
						iocleubd.3    ⊢   φ   →   C  ∈   A  B           
					 
				
					Assertion 
					iocleubd    ⊢   φ   →   C  ≤  B         
				 
			
		 
		
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1 
								
							 
							iocleubd.1   ⊢   φ   →   A  ∈    ℝ   *           
						
							2 
								
							 
							iocleubd.2   ⊢   φ   →   B  ∈    ℝ   *           
						
							3 
								
							 
							iocleubd.3   ⊢   φ   →   C  ∈   A  B           
						
							4 
								
							 
							iocleub   ⊢    A  ∈    ℝ   *      ∧   B  ∈    ℝ   *      ∧   C  ∈   A  B       →   C  ≤  B         
						
							5 
								1  2  3  4 
							 
							syl3anc   ⊢   φ   →   C  ≤  B