const A: Int = callIncrement(10);

fun callIncrement(v: Int): Int {
    return v.incr();   // Execution fails here because v does not have yet a type registered in CompilerContext
}                      // and it is required in order to obtain function incr assigned to reference type Int.

extends fun incr(self: Int): Int {
    self += 1;
    return self;
}

Error: [INTERNAL COMPILER ERROR]: Expression 1784 not found
Please report at https://github.com/tact-lang/tact/issues
    at throwInternalCompilerError (/home/jesus/tact/tact/src/error/errors.ts:66:11)
    at getExpType (/home/jesus/tact/tact/src/types/resolveExpression.ts:37:35)
    at Interpreter.interpretMethodCall (/home/jesus/tact/tact/src/optimizer/interpreter.ts:943:41)
    at Interpreter.interpretExpression (/home/jesus/tact/tact/src/optimizer/interpreter.ts:851:29)
.....

fun callIncrement(v: Int): Int {
    return 10.incr();   // Execution fails here because 10 does not have yet a type registered in CompilerContext
}