Mel

Mel (Minsky machine equivalent language) is an esolang invented by User:None1.

Commands

Every line is a command:

+++...+<accumulator name>

Increases the accumulator by the number of +'s.

For example:

+++A

Adds A by 3.

---...-<accumulator name>

If accumulator is not zero, decrement the accumulator, otherwise jump to line x, where x is the number of -'s (1-indexed).

For example:

---B

Decrements B if it's nonzero, otherwise jumps to line 3.

There are two accumulators: A and B, they are both unbounded. Programs are case-insensitive.

Translation from minsky machine

It can be easily translated, for example, this minsky machine program, in Szewczyk notation for Minsky machine notation:

1 -1
1 1
1 1

Can be translated to:

+A
-A
-A

So, it is Turing complete.

Interpreter in Python

import sys
c=sys.stdin.read().lower().strip().split('\n')
ip=0
acc=[0,0]
while ip<len(c):
    cmd=c[ip]
    idx=(0 if cmd[-1]=='a' else 1)
    if cmd[0]=='+':
        ip+=1
        acc[idx]+=len(cmd)-1
    else:
        if acc[idx]:
            acc[idx]-=1
            ip+=1
        else:
            ip=len(cmd)-2
    # print('a={} b={}'.format(*acc))