how to find gap in a range.

I use sql 2012 but, one can answer up to 2019
create table t ( b decimal(13,4) not null, c decimal(13,4) not null);
Insert into T (B,C) values ( 1,200);
Insert into T (B,C) values ( 200 ,400);
Insert into T (B,C) values ( 600, 900);
create table t1 (b decimal(13,4) not null, c decimal(13,4) not null);
Insert into t1 (B,C) values ( 1,100);
Insert into t1 (B,C) values ( 200 ,500);
Insert into t1 (B,C) values ( 800, 1000);
-- "t" and "t1" table holds ranges which could be any thing where b<c, i have to find out where "t" has range but "t1" does not?
--ex "t" has 1,200 , "t1" 1,100 so i want to see 100 to 200 t2 does not have any thing.
Q) i have to find out the range where "t" has got range but "t1" does not? that means start range and end range will be passed
and i have to find out the range where "t1" is not done but "t" is done
-- case 1 table "t" and "t1" will have no overlap with in the table
-- case 2 they will have overlap with in the table.
result
100 -200
600 - 800
yours sincerley
Answers
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