:: L_HOSPIT semantic presentation

theorem Th1: :: L_HOSPIT:1
for b1 being PartFunc of REAL , REAL
for b2 being Real st b1 is_continuous_in b2 & ( for b3, b4 being Real st b3 < b2 & b2 < b4 holds
ex b5, b6 being Real st
( b3 < b5 & b5 < b2 & b5 in dom b1 & b6 < b4 & b2 < b6 & b6 in dom b1 ) ) holds
b1 is_convergent_in b2
proof end;

theorem Th2: :: L_HOSPIT:2
for b1 being PartFunc of REAL , REAL
for b2, b3 being Real holds
( b1 is_right_convergent_in b2 & lim_right b1,b2 = b3 iff ( ( for b4 being Real st b2 < b4 holds
ex b5 being Real st
( b5 < b4 & b2 < b5 & b5 in dom b1 ) ) & ( for b4 being Real_Sequence st b4 is convergent & lim b4 = b2 & rng b4 c= (dom b1) /\ (right_open_halfline b2) holds
( b1 * b4 is convergent & lim (b1 * b4) = b3 ) ) ) )
proof end;

theorem Th3: :: L_HOSPIT:3
for b1 being PartFunc of REAL , REAL
for b2, b3 being Real holds
( b1 is_left_convergent_in b2 & lim_left b1,b2 = b3 iff ( ( for b4 being Real st b4 < b2 holds
ex b5 being Real st
( b4 < b5 & b5 < b2 & b5 in dom b1 ) ) & ( for b4 being Real_Sequence st b4 is convergent & lim b4 = b2 & rng b4 c= (dom b1) /\ (left_open_halfline b2) holds
( b1 * b4 is convergent & lim (b1 * b4) = b3 ) ) ) )
proof end;

theorem Th4: :: L_HOSPIT:4
for b1 being PartFunc of REAL , REAL
for b2 being Real st ex b3 being Neighbourhood of b2 st b3 \ {b2} c= dom b1 holds
for b3, b4 being Real st b3 < b2 & b2 < b4 holds
ex b5, b6 being Real st
( b3 < b5 & b5 < b2 & b5 in dom b1 & b6 < b4 & b2 < b6 & b6 in dom b1 )
proof end;

theorem Th5: :: L_HOSPIT:5
for b1, b2 being PartFunc of REAL , REAL
for b3 being Real st ex b4 being Neighbourhood of b3 st
( b1 is_differentiable_on b4 & b2 is_differentiable_on b4 & b4 \ {b3} c= dom (b1 / b2) & b4 c= dom ((b1 `| b4) / (b2 `| b4)) & b1 . b3 = 0 & b2 . b3 = 0 & (b1 `| b4) / (b2 `| b4) is_divergent_to+infty_in b3 ) holds
b1 / b2 is_divergent_to+infty_in b3
proof end;

theorem Th6: :: L_HOSPIT:6
for b1, b2 being PartFunc of REAL , REAL
for b3 being Real st ex b4 being Neighbourhood of b3 st
( b1 is_differentiable_on b4 & b2 is_differentiable_on b4 & b4 \ {b3} c= dom (b1 / b2) & b4 c= dom ((b1 `| b4) / (b2 `| b4)) & b1 . b3 = 0 & b2 . b3 = 0 & (b1 `| b4) / (b2 `| b4) is_divergent_to-infty_in b3 ) holds
b1 / b2 is_divergent_to-infty_in b3
proof end;

theorem Th7: :: L_HOSPIT:7
for b1, b2 being PartFunc of REAL , REAL
for b3 being Real st ex b4 being Real st
( b4 > 0 & b1 is_differentiable_on ].b3,(b3 + b4).[ & b2 is_differentiable_on ].b3,(b3 + b4).[ & ].b3,(b3 + b4).[ c= dom (b1 / b2) & [.b3,(b3 + b4).] c= dom ((b1 `| ].b3,(b3 + b4).[) / (b2 `| ].b3,(b3 + b4).[)) & b1 . b3 = 0 & b2 . b3 = 0 & b1 is_continuous_in b3 & b2 is_continuous_in b3 & (b1 `| ].b3,(b3 + b4).[) / (b2 `| ].b3,(b3 + b4).[) is_right_convergent_in b3 ) holds
( b1 / b2 is_right_convergent_in b3 & ex b4 being Real st
( b4 > 0 & lim_right (b1 / b2),b3 = lim_right ((b1 `| ].b3,(b3 + b4).[) / (b2 `| ].b3,(b3 + b4).[)),b3 ) )
proof end;

theorem Th8: :: L_HOSPIT:8
for b1, b2 being PartFunc of REAL , REAL
for b3 being Real st ex b4 being Real st
( b4 > 0 & b1 is_differentiable_on ].(b3 - b4),b3.[ & b2 is_differentiable_on ].(b3 - b4),b3.[ & ].(b3 - b4),b3.[ c= dom (b1 / b2) & [.(b3 - b4),b3.] c= dom ((b1 `| ].(b3 - b4),b3.[) / (b2 `| ].(b3 - b4),b3.[)) & b1 . b3 = 0 & b2 . b3 = 0 & b1 is_continuous_in b3 & b2 is_continuous_in b3 & (b1 `| ].(b3 - b4),b3.[) / (b2 `| ].(b3 - b4),b3.[) is_left_convergent_in b3 ) holds
( b1 / b2 is_left_convergent_in b3 & ex b4 being Real st
( b4 > 0 & lim_left (b1 / b2),b3 = lim_left ((b1 `| ].(b3 - b4),b3.[) / (b2 `| ].(b3 - b4),b3.[)),b3 ) )
proof end;

theorem Th9: :: L_HOSPIT:9
for b1, b2 being PartFunc of REAL , REAL
for b3 being Real st ex b4 being Neighbourhood of b3 st
( b1 is_differentiable_on b4 & b2 is_differentiable_on b4 & b4 \ {b3} c= dom (b1 / b2) & b4 c= dom ((b1 `| b4) / (b2 `| b4)) & b1 . b3 = 0 & b2 . b3 = 0 & (b1 `| b4) / (b2 `| b4) is_convergent_in b3 ) holds
( b1 / b2 is_convergent_in b3 & ex b4 being Neighbourhood of b3 st lim (b1 / b2),b3 = lim ((b1 `| b4) / (b2 `| b4)),b3 )
proof end;

theorem Th10: :: L_HOSPIT:10
for b1, b2 being PartFunc of REAL , REAL
for b3 being Real st ex b4 being Neighbourhood of b3 st
( b1 is_differentiable_on b4 & b2 is_differentiable_on b4 & b4 \ {b3} c= dom (b1 / b2) & b4 c= dom ((b1 `| b4) / (b2 `| b4)) & b1 . b3 = 0 & b2 . b3 = 0 & (b1 `| b4) / (b2 `| b4) is_continuous_in b3 ) holds
( b1 / b2 is_convergent_in b3 & lim (b1 / b2),b3 = (diff b1,b3) / (diff b2,b3) )
proof end;