Q9.2

Problem 1.  
Premise 1 (Iab&Iba)&Ibc
1 &E 2 Iab&Iba
2 &E 3 Iab
1 &E 4 Ibc
3,4 I3 5 Iac
Problem 2.  
Premise 1 (^x)(Gcd>Txd)
Premise 2 Ikc&Gkd
2 &E 3 Ikc
2 &E 4 Gkd
3,4 I4 5 Gcd
1 ^E 6 Gcd>Tad
5,6 >E 7 Tad
Problem 3.  
I1 1 Iaa
1 ^I 2 (^x)Ixx
Problem 4.  
Premise 1 Iba
1 I2 2 Iab
~~~~ 3 ~ part II ~
Premise 4 Iab
6 I2 5 Iba

9.2ex I

Problem 1.  
Premise 1 Iab&Sbc
Premise 2 (^x)(Sac>Z)
1 &E 3 Iab
1 &E 4 Sbc
3 I2 5 Iba
4,5 I4 6 Sac
2 ^E 7 Sac>Z
6,7 >E 8 Z
Problem 2.  
Assumption 1 ....what if Iab
1 I2 2 ....then... Iba
1-2 >I 3 Iab>Iba  
Assumption 4 ....what if Iba
4 I2 5 ....then... Iab
4-5 >I 6 Iba>Iab  
3,6 =I 7 Iab=Iba  
7 ^I 8 (^y)(Iay=Iya)  
Problem 4.  
Premise 1 Iab&Iba
1 &E 2 Iab
  3  
  4  
  5  
  6  
~~~~ 7 ~ part II ~
Premise 8 Iab
8 I2 9 Iba
  10  
  11  
8,9 &I 12 Iab&Iba