Theorem List for Intuitionistic Logic Explorer - 9001-9100 *Has distinct variable
group(s)
| Type | Label | Description |
| Statement |
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| Theorem | div11apd 9001 |
One-to-one relationship for division. (Contributed by Jim Kingdon,
2-Mar-2020.)
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       #           |
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| Theorem | divmuldivapd 9002 |
Multiplication of two ratios. (Contributed by Jim Kingdon,
30-Jul-2021.)
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         #   #           
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| Theorem | divmuleqapd 9003 |
Cross-multiply in an equality of ratios. (Contributed by Mario
Carneiro, 27-May-2016.)
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         #   #     
   
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| Theorem | rerecclapd 9004 |
Closure law for reciprocal. (Contributed by Jim Kingdon,
29-Feb-2020.)
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   #   
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| Theorem | redivclapd 9005 |
Closure law for division of reals. (Contributed by Jim Kingdon,
29-Feb-2020.)
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     #
   
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| Theorem | diveqap1bd 9006 |
If two complex numbers are equal, their quotient is one. One-way
deduction form of diveqap1 8875. Converse of diveqap1d 8968. (Contributed
by David Moews, 28-Feb-2017.) (Revised by Jim Kingdon, 2-Aug-2023.)
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   #         |
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| Theorem | div2subap 9007 |
Swap the order of subtraction in a division. (Contributed by Scott
Fenton, 24-Jun-2013.)
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#  
        
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| Theorem | div2subapd 9008 |
Swap subtrahend and minuend inside the numerator and denominator of a
fraction. Deduction form of div2subap 9007. (Contributed by David Moews,
28-Feb-2017.)
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         #           
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| Theorem | subrecap 9009 |
Subtraction of reciprocals. (Contributed by Scott Fenton, 9-Jul-2015.)
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   # 
 #     

          |
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| Theorem | subrecapi 9010 |
Subtraction of reciprocals. (Contributed by Scott Fenton,
9-Jan-2017.)
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# #   

         |
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| Theorem | subrecapd 9011 |
Subtraction of reciprocals. (Contributed by Scott Fenton,
9-Jan-2017.)
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     #
  #
       
        |
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| Theorem | mvllmulapd 9012 |
Move LHS left multiplication to RHS. (Contributed by Jim Kingdon,
10-Jun-2020.)
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     #
   
      |
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| Theorem | rerecapb 9013* |
A real number has a multiplicative inverse if and only if it is apart
from zero. Theorem 11.2.4 of [HoTT], p.
(varies). (Contributed by Jim
Kingdon, 18-Jan-2025.)
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  #  

   |
| |
| 4.3.9 Ordering on reals (cont.)
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| Theorem | ltp1 9014 |
A number is less than itself plus 1. (Contributed by NM, 20-Aug-2001.)
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| Theorem | lep1 9015 |
A number is less than or equal to itself plus 1. (Contributed by NM,
5-Jan-2006.)
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| Theorem | ltm1 9016 |
A number minus 1 is less than itself. (Contributed by NM, 9-Apr-2006.)
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| Theorem | lem1 9017 |
A number minus 1 is less than or equal to itself. (Contributed by Mario
Carneiro, 2-Oct-2015.)
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| Theorem | letrp1 9018 |
A transitive property of 'less than or equal' and plus 1. (Contributed by
NM, 5-Aug-2005.)
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| Theorem | p1le 9019 |
A transitive property of plus 1 and 'less than or equal'. (Contributed by
NM, 16-Aug-2005.)
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| Theorem | recgt0 9020 |
The reciprocal of a positive number is positive. Exercise 4 of [Apostol]
p. 21. (Contributed by NM, 25-Aug-1999.) (Revised by Mario Carneiro,
27-May-2016.)
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| Theorem | prodgt0gt0 9021 |
Infer that a multiplicand is positive from a positive multiplier and
positive product. See prodgt0 9022 for the same theorem with
replaced by the weaker condition
. (Contributed by Jim
Kingdon, 29-Feb-2020.)
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| Theorem | prodgt0 9022 |
Infer that a multiplicand is positive from a nonnegative multiplier and
positive product. (Contributed by NM, 24-Apr-2005.) (Revised by Mario
Carneiro, 27-May-2016.)
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| Theorem | prodgt02 9023 |
Infer that a multiplier is positive from a nonnegative multiplicand and
positive product. (Contributed by NM, 24-Apr-2005.)
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| Theorem | prodge0 9024 |
Infer that a multiplicand is nonnegative from a positive multiplier and
nonnegative product. (Contributed by NM, 2-Jul-2005.) (Revised by Mario
Carneiro, 27-May-2016.)
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| Theorem | prodge02 9025 |
Infer that a multiplier is nonnegative from a positive multiplicand and
nonnegative product. (Contributed by NM, 2-Jul-2005.)
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| Theorem | ltmul2 9026 |
Multiplication of both sides of 'less than' by a positive number. Theorem
I.19 of [Apostol] p. 20. (Contributed by
NM, 13-Feb-2005.)
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| Theorem | lemul2 9027 |
Multiplication of both sides of 'less than or equal to' by a positive
number. (Contributed by NM, 16-Mar-2005.)
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| Theorem | lemul1a 9028 |
Multiplication of both sides of 'less than or equal to' by a nonnegative
number. Part of Definition 11.2.7(vi) of [HoTT], p. (varies).
(Contributed by NM, 21-Feb-2005.)
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| Theorem | lemul2a 9029 |
Multiplication of both sides of 'less than or equal to' by a nonnegative
number. (Contributed by Paul Chapman, 7-Sep-2007.)
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| Theorem | ltmul12a 9030 |
Comparison of product of two positive numbers. (Contributed by NM,
30-Dec-2005.)
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| Theorem | lemul12b 9031 |
Comparison of product of two nonnegative numbers. (Contributed by NM,
22-Feb-2008.)
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| Theorem | lemul12a 9032 |
Comparison of product of two nonnegative numbers. (Contributed by NM,
22-Feb-2008.)
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| Theorem | mulgt1 9033 |
The product of two numbers greater than 1 is greater than 1. (Contributed
by NM, 13-Feb-2005.)
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| Theorem | ltmulgt11 9034 |
Multiplication by a number greater than 1. (Contributed by NM,
24-Dec-2005.)
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         |
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| Theorem | ltmulgt12 9035 |
Multiplication by a number greater than 1. (Contributed by NM,
24-Dec-2005.)
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         |
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| Theorem | lemulge11 9036 |
Multiplication by a number greater than or equal to 1. (Contributed by
NM, 17-Dec-2005.)
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| Theorem | lemulge12 9037 |
Multiplication by a number greater than or equal to 1. (Contributed by
Paul Chapman, 21-Mar-2011.)
|
    
 
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| Theorem | ltdiv1 9038 |
Division of both sides of 'less than' by a positive number. (Contributed
by NM, 10-Oct-2004.) (Revised by Mario Carneiro, 27-May-2016.)
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| Theorem | lediv1 9039 |
Division of both sides of a less than or equal to relation by a positive
number. (Contributed by NM, 18-Nov-2004.)
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| Theorem | gt0div 9040 |
Division of a positive number by a positive number. (Contributed by NM,
28-Sep-2005.)
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         |
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| Theorem | ge0div 9041 |
Division of a nonnegative number by a positive number. (Contributed by
NM, 28-Sep-2005.)
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         |
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| Theorem | divgt0 9042 |
The ratio of two positive numbers is positive. (Contributed by NM,
12-Oct-1999.)
|
    
 
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| Theorem | divge0 9043 |
The ratio of nonnegative and positive numbers is nonnegative.
(Contributed by NM, 27-Sep-1999.)
|
    
 
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| Theorem | ltmuldiv 9044 |
'Less than' relationship between division and multiplication.
(Contributed by NM, 12-Oct-1999.) (Proof shortened by Mario Carneiro,
27-May-2016.)
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| Theorem | ltmuldiv2 9045 |
'Less than' relationship between division and multiplication.
(Contributed by NM, 18-Nov-2004.)
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| Theorem | ltdivmul 9046 |
'Less than' relationship between division and multiplication.
(Contributed by NM, 18-Nov-2004.)
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| Theorem | ledivmul 9047 |
'Less than or equal to' relationship between division and multiplication.
(Contributed by NM, 9-Dec-2005.)
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| Theorem | ltdivmul2 9048 |
'Less than' relationship between division and multiplication.
(Contributed by NM, 24-Feb-2005.)
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| Theorem | lt2mul2div 9049 |
'Less than' relationship between division and multiplication.
(Contributed by NM, 8-Jan-2006.)
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| Theorem | ledivmul2 9050 |
'Less than or equal to' relationship between division and multiplication.
(Contributed by NM, 9-Dec-2005.)
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| Theorem | lemuldiv 9051 |
'Less than or equal' relationship between division and multiplication.
(Contributed by NM, 10-Mar-2006.)
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| Theorem | lemuldiv2 9052 |
'Less than or equal' relationship between division and multiplication.
(Contributed by NM, 10-Mar-2006.)
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| Theorem | ltrec 9053 |
The reciprocal of both sides of 'less than'. (Contributed by NM,
26-Sep-1999.) (Revised by Mario Carneiro, 27-May-2016.)
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| Theorem | lerec 9054 |
The reciprocal of both sides of 'less than or equal to'. (Contributed by
NM, 3-Oct-1999.) (Proof shortened by Mario Carneiro, 27-May-2016.)
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| Theorem | lt2msq1 9055 |
Lemma for lt2msq 9056. (Contributed by Mario Carneiro,
27-May-2016.)
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| Theorem | lt2msq 9056 |
Two nonnegative numbers compare the same as their squares. (Contributed
by Roy F. Longton, 8-Aug-2005.) (Revised by Mario Carneiro,
27-May-2016.)
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| Theorem | ltdiv2 9057 |
Division of a positive number by both sides of 'less than'. (Contributed
by NM, 27-Apr-2005.)
|
    
 
  
 
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| Theorem | ltrec1 9058 |
Reciprocal swap in a 'less than' relation. (Contributed by NM,
24-Feb-2005.)
|
    
    
 
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| Theorem | lerec2 9059 |
Reciprocal swap in a 'less than or equal to' relation. (Contributed by
NM, 24-Feb-2005.)
|
    
  
 
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| Theorem | ledivdiv 9060 |
Invert ratios of positive numbers and swap their ordering. (Contributed
by NM, 9-Jan-2006.)
|
     
     
       
 
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| Theorem | lediv2 9061 |
Division of a positive number by both sides of 'less than or equal to'.
(Contributed by NM, 10-Jan-2006.)
|
    
 
  
 
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| Theorem | ltdiv23 9062 |
Swap denominator with other side of 'less than'. (Contributed by NM,
3-Oct-1999.)
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| Theorem | lediv23 9063 |
Swap denominator with other side of 'less than or equal to'. (Contributed
by NM, 30-May-2005.)
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| Theorem | lediv12a 9064 |
Comparison of ratio of two nonnegative numbers. (Contributed by NM,
31-Dec-2005.)
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      |
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| Theorem | lediv2a 9065 |
Division of both sides of 'less than or equal to' into a nonnegative
number. (Contributed by Paul Chapman, 7-Sep-2007.)
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| Theorem | reclt1 9066 |
The reciprocal of a positive number less than 1 is greater than 1.
(Contributed by NM, 23-Feb-2005.)
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| Theorem | recgt1 9067 |
The reciprocal of a positive number greater than 1 is less than 1.
(Contributed by NM, 28-Dec-2005.)
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         |
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| Theorem | recgt1i 9068 |
The reciprocal of a number greater than 1 is positive and less than 1.
(Contributed by NM, 23-Feb-2005.)
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| Theorem | recp1lt1 9069 |
Construct a number less than 1 from any nonnegative number. (Contributed
by NM, 30-Dec-2005.)
|
      
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| Theorem | recreclt 9070 |
Given a positive number , construct a new positive number less than
both and 1.
(Contributed by NM, 28-Dec-2005.)
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| Theorem | le2msq 9071 |
The square function on nonnegative reals is monotonic. (Contributed by
NM, 3-Aug-1999.) (Proof shortened by Mario Carneiro, 27-May-2016.)
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| Theorem | msq11 9072 |
The square of a nonnegative number is a one-to-one function. (Contributed
by NM, 29-Jul-1999.) (Revised by Mario Carneiro, 27-May-2016.)
|
    
    
 
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| Theorem | ledivp1 9073 |
Less-than-or-equal-to and division relation. (Lemma for computing upper
bounds of products. The "+ 1" prevents division by zero.)
(Contributed
by NM, 28-Sep-2005.)
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| Theorem | squeeze0 9074* |
If a nonnegative number is less than any positive number, it is zero.
(Contributed by NM, 11-Feb-2006.)
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| Theorem | ltp1i 9075 |
A number is less than itself plus 1. (Contributed by NM,
20-Aug-2001.)
|

  |
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| Theorem | recgt0i 9076 |
The reciprocal of a positive number is positive. Exercise 4 of
[Apostol] p. 21. (Contributed by NM,
15-May-1999.)
|
 
   |
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| Theorem | recgt0ii 9077 |
The reciprocal of a positive number is positive. Exercise 4 of
[Apostol] p. 21. (Contributed by NM,
15-May-1999.)
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   |
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| Theorem | prodgt0i 9078 |
Infer that a multiplicand is positive from a nonnegative multiplier and
positive product. (Contributed by NM, 15-May-1999.)
|
    
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| Theorem | prodge0i 9079 |
Infer that a multiplicand is nonnegative from a positive multiplier and
nonnegative product. (Contributed by NM, 2-Jul-2005.)
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| Theorem | divgt0i 9080 |
The ratio of two positive numbers is positive. (Contributed by NM,
16-May-1999.)
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       |
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| Theorem | divge0i 9081 |
The ratio of nonnegative and positive numbers is nonnegative.
(Contributed by NM, 12-Aug-1999.)
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       |
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| Theorem | ltreci 9082 |
The reciprocal of both sides of 'less than'. (Contributed by NM,
15-Sep-1999.)
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           |
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| Theorem | lereci 9083 |
The reciprocal of both sides of 'less than or equal to'. (Contributed
by NM, 16-Sep-1999.)
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           |
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| Theorem | lt2msqi 9084 |
The square function on nonnegative reals is strictly monotonic.
(Contributed by NM, 3-Aug-1999.)
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| Theorem | le2msqi 9085 |
The square function on nonnegative reals is monotonic. (Contributed by
NM, 2-Aug-1999.)
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           |
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| Theorem | msq11i 9086 |
The square of a nonnegative number is a one-to-one function.
(Contributed by NM, 29-Jul-1999.)
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           |
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| Theorem | divgt0i2i 9087 |
The ratio of two positive numbers is positive. (Contributed by NM,
16-May-1999.)
|

    |
| |
| Theorem | ltrecii 9088 |
The reciprocal of both sides of 'less than'. (Contributed by NM,
15-Sep-1999.)
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       |
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| Theorem | divgt0ii 9089 |
The ratio of two positive numbers is positive. (Contributed by NM,
18-May-1999.)
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   |
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| Theorem | ltmul1i 9090 |
Multiplication of both sides of 'less than' by a positive number.
Theorem I.19 of [Apostol] p. 20.
(Contributed by NM, 16-May-1999.)
|

  
     |
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| Theorem | ltdiv1i 9091 |
Division of both sides of 'less than' by a positive number.
(Contributed by NM, 16-May-1999.)
|

  
     |
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| Theorem | ltmuldivi 9092 |
'Less than' relationship between division and multiplication.
(Contributed by NM, 12-Oct-1999.)
|

  
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| Theorem | ltmul2i 9093 |
Multiplication of both sides of 'less than' by a positive number.
Theorem I.19 of [Apostol] p. 20.
(Contributed by NM, 16-May-1999.)
|

  
     |
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| Theorem | lemul1i 9094 |
Multiplication of both sides of 'less than or equal to' by a positive
number. (Contributed by NM, 2-Aug-1999.)
|


 
     |
| |
| Theorem | lemul2i 9095 |
Multiplication of both sides of 'less than or equal to' by a positive
number. (Contributed by NM, 1-Aug-1999.)
|


 
     |
| |
| Theorem | ltdiv23i 9096 |
Swap denominator with other side of 'less than'. (Contributed by NM,
26-Sep-1999.)
|
 
   
 
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| |
| Theorem | ltdiv23ii 9097 |
Swap denominator with other side of 'less than'. (Contributed by NM,
26-Sep-1999.)
|
    
  |
| |
| Theorem | ltmul1ii 9098 |
Multiplication of both sides of 'less than' by a positive number.
Theorem I.19 of [Apostol] p. 20.
(Contributed by NM, 16-May-1999.)
(Proof shortened by Paul Chapman, 25-Jan-2008.)
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| Theorem | ltdiv1ii 9099 |
Division of both sides of 'less than' by a positive number.
(Contributed by NM, 16-May-1999.)
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| Theorem | ltp1d 9100 |
A number is less than itself plus 1. (Contributed by Mario Carneiro,
28-May-2016.)
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