Discrete Mathematics question

Question

Answer 1

(1)Upper bound of S1 = { 3 , 4 , 5 , 6 , 7 , 8 }

A lower bound of S1 =not Exists

Upper bound of S2 = { 6 , 7 , 8 }

Lower bound of S2 = { 1, 2, 3 }

(2)GLB(S1)=not Exists

LUB(S1)=3

GLB(S2)= 3

LUB(S2)=not Exist as both 6 and 7 are upper bounds and they are not related.

Comments

Why there is 3 in lower bound of S2={3,4,5}

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LUB for S1 is 3 and LUB for S2 is 8 or not exist ?

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LUB(S2) is not existing. Answer is edited.

Answer 2

S1 = {1, 2}

S2 = {3, 4, 5}

(i)

Upper Bound of S1 = {3, 4, 5, 6, 7, 8}

Lower Bound of S1 = Does Not Exist (Since there are no elements below them to Meet)

Upper Bound of S2 = {6, 7, 8}

Lower Bound of S2 = {1, 2, 3}

(ii)

GLB of S1 = Does Not Exist (Since there are no elements below them)

LUB of S1 = {3}

GLB of S2 = {3}

LUB of S2 = Does Not Exist (Since there is No Unique first Joining point)