[Scip] input file format

[Raphael C]

I have created this small test MIP

Minimize
x00 + x01 + x10 + x11
Subject To
('x01 + x11', '>=', 1)
('x10 + x11', '>=', 1)
('x10 + x00', '>=', 1)
('x01 + x00', '>=', 1)
('x01 + x10 + x11', '>=', 1)
('x00', '>=', 1)
('x01 + x10 + x00', '>=', 1)
('x11', '>=', 1)
Binary
x00
x01
x10
x11
End


When I do scip -f test.lp  I get [src/scip/reader_lp.c:127] ERROR:
Syntax error in line 4 ('''): expected sign ('+' or '-') or sense ('<'
or '>').
  input: ('x01 + x11', '>=', 1)


What should the file look like?

Raphael