A family of 5 stuck in a perpetual time loop of agony

A family of 5 stuck in a perpetual time loop of agony is an esoteric programming language made by User:Dragoneater67 in 2026. It was inspired by But Is It Art?.

Syntax

The source is a 2d grid of symbols. For each unique symbol, find the rectangle that contains the largest contiguous shape that only consists of the symbol, and define it as a subprogram. For example, the program:

AAAAAAA
ABCCCCA
ABBBBCA
AAAAAAA

defines 3 subprograms: Subprogram A

AAAAAAA
ABCCCCA
ABBBBCA
AAAAAAA

Subprogram B

BCCC
BBBB

Subprogram C

CCCC
BBBC

Execution

The program executes subprograms in order from biggest to smallest in an implicit infinite loop. To execute a subprogram is to replace the first appearance of each symbol (in order from biggest to smallest) with its corresponding subprogram, the newly created rows and columns are padded with spaces with preference on the right and bottom sides. For example:

Subprogram A

AAB
BAA

Subprogram B

ABB
BBA

Execute subprogram A

AAB
BAAAB
  BAA

AAABB
  BBA
BAAAB
  BAA

Execute subprogram B

AAABB
  BBA
BAAAB
  BAABB
    BBA

AAAAAABB  B
     BBA
   BAAAB
     BAABB
       BBA
  B       BA
BAA       AB
  B       AABB
           BBA

Examples

Infinitely growing 7

AB
BB

Subprogram A

A

Subprogram B

AB
BB

Execution trace for A

A

A

A

A

...

Execution trace for B

AB
BB

AAB
 BB
BB

AAAAB
   BB
  BB
 BB
BB

AAAAAAAAB
       BB
      BB
     BB
    BB
   BB
  BB
 BB
BB

...